refactor(merge,split,json): adopt streaming approach and standardize types, address gradle warnings (#5803)

Co-authored-by: Anthony Stirling <[email protected]>
Co-authored-by: Balázs <[email protected]>

app/common/src/main/java/stirling/software/SPDF/config/EndpointConfiguration.java

@@ -103,8 +103,9 @@ public class EndpointConfiguration {
 
         // Rule 2: Functional-group override - check if endpoint belongs to any disabled functional
         // group
-        for (String group : endpointGroups.keySet()) {
-            if (disabledGroups.contains(group) && endpointGroups.get(group).contains(endpoint)) {
+        for (Map.Entry<String, Set<String>> entry : endpointGroups.entrySet()) {
+            String group = entry.getKey();
+            if (disabledGroups.contains(group) && entry.getValue().contains(endpoint)) {
                 // Skip tool groups (qpdf, OCRmyPDF, Ghostscript, LibreOffice, etc.)
                 if (!isToolGroup(group)) {
                     log.debug(
@@ -131,10 +132,11 @@ public class EndpointConfiguration {
 
         // Rule 4: Single-dependency check - if no alternatives defined, check if endpoint belongs
         // to any disabled tool groups
-        for (String group : endpointGroups.keySet()) {
+        for (Map.Entry<String, Set<String>> entry : endpointGroups.entrySet()) {
+            String group = entry.getKey();
             if (isToolGroup(group)
                     && disabledGroups.contains(group)
-                    && endpointGroups.get(group).contains(endpoint)) {
+                    && entry.getValue().contains(endpoint)) {
                 log.debug(
                         "isEndpointEnabled('{}') -> false (single tool group '{}' disabled, no alternatives)",
                         original,
@@ -645,8 +647,9 @@ public class EndpointConfiguration {
         }
 
         // Check if endpoint belongs to any disabled functional group
-        for (String group : endpointGroups.keySet()) {
-            if (disabledGroups.contains(group) && endpointGroups.get(group).contains(endpoint)) {
+        for (Map.Entry<String, Set<String>> entry : endpointGroups.entrySet()) {
+            String group = entry.getKey();
+            if (disabledGroups.contains(group) && entry.getValue().contains(endpoint)) {
                 if (!isToolGroup(group)) {
                     return false;
                 }

app/common/src/main/java/stirling/software/common/model/ApplicationProperties.java

@@ -365,11 +365,11 @@ public class ApplicationProperties {
             }
 
             public boolean isSettingsValid() {
-                return !ValidationUtils.isStringEmpty(this.getIssuer())
-                        && !ValidationUtils.isStringEmpty(this.getClientId())
-                        && !ValidationUtils.isStringEmpty(this.getClientSecret())
-                        && !ValidationUtils.isCollectionEmpty(this.getScopes())
-                        && !ValidationUtils.isStringEmpty(this.getUseAsUsername());
+                return !ValidationUtils.isStringEmpty(this.issuer)
+                        && !ValidationUtils.isStringEmpty(this.clientId)
+                        && !ValidationUtils.isStringEmpty(this.clientSecret)
+                        && !ValidationUtils.isCollectionEmpty(this.scopes)
+                        && !ValidationUtils.isStringEmpty(this.useAsUsername);
             }
 
             @Data
@@ -575,19 +575,17 @@ public class ApplicationProperties {
         }
 
         public boolean isAnalyticsEnabled() {
-            return this.getEnableAnalytics() != null && this.getEnableAnalytics();
+            return this.enableAnalytics != null && this.enableAnalytics;
         }
 
         public boolean isPosthogEnabled() {
             // Treat null as enabled when analytics is enabled
-            return this.isAnalyticsEnabled()
-                    && (this.getEnablePosthog() == null || this.getEnablePosthog());
+            return this.isAnalyticsEnabled() && (this.enablePosthog == null || this.enablePosthog);
         }
 
         public boolean isScarfEnabled() {
             // Treat null as enabled when analytics is enabled
-            return this.isAnalyticsEnabled()
-                    && (this.getEnableScarf() == null || this.getEnableScarf());
+            return this.isAnalyticsEnabled() && (this.enableScarf == null || this.enableScarf);
         }
     }
 

app/common/src/main/java/stirling/software/common/model/enumeration/Role.java

@@ -42,7 +42,7 @@ public enum Role {
         // Using the fromString method to get the Role enum based on the roleId
         Role role = fromString(roleId);
         // Return the roleName of the found Role enum
-        return role.getRoleName();
+        return role.roleName;
     }
 
     // Method to retrieve all role IDs and role names
@@ -50,14 +50,14 @@ public enum Role {
         // Using LinkedHashMap to preserve order
         Map<String, String> roleDetails = new LinkedHashMap<>();
         for (Role role : Role.values()) {
-            roleDetails.put(role.getRoleId(), role.getRoleName());
+            roleDetails.put(role.roleId, role.roleName);
         }
         return roleDetails;
     }
 
     public static Role fromString(String roleId) {
         for (Role role : Role.values()) {
-            if (role.getRoleId().equalsIgnoreCase(roleId)) {
+            if (role.roleId.equalsIgnoreCase(roleId)) {
                 return role;
             }
         }

app/common/src/main/java/stirling/software/common/model/oauth2/Provider.java

@@ -117,13 +117,13 @@ public class Provider {
                 + ", clientName="
                 + getClientName()
                 + ", clientId="
-                + getClientId()
+                + clientId
                 + ", clientSecret="
-                + (getClientSecret() != null && !getClientSecret().isEmpty() ? "*****" : "NULL")
+                + (clientSecret != null && !clientSecret.isEmpty() ? "*****" : "NULL")
                 + ", scopes="
                 + getScopes()
                 + ", useAsUsername="
-                + getUseAsUsername()
+                + useAsUsername
                 + "]";
     }
 }

app/common/src/main/java/stirling/software/common/service/FileStorage.java

@@ -1,6 +1,8 @@
 package stirling.software.common.service;
 
+import java.io.BufferedInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.UUID;
@@ -21,6 +23,9 @@ import lombok.extern.slf4j.Slf4j;
 @Slf4j
 public class FileStorage {
 
+    /** Holds the result of a stream-to-disk store operation: the file ID and the bytes written. */
+    public record StoredFile(String fileId, long size) {}
+
     @Value("${stirling.tempDir:/tmp/stirling-files}")
     private String tempDirPath;
 
@@ -104,6 +109,40 @@ public class FileStorage {
         return Files.readAllBytes(filePath);
     }
 
+    /**
+     * Retrieve a file by its ID as a streaming InputStream. The caller is responsible for closing
+     * the returned stream.
+     *
+     * @param fileId The ID of the file to retrieve
+     * @return A buffered InputStream for the file
+     * @throws IOException If the file doesn't exist or can't be read
+     */
+    public InputStream retrieveInputStream(String fileId) throws IOException {
+        Path filePath = getFilePath(fileId);
+        // Let Files.newInputStream throw NoSuchFileException naturally — avoids TOCTOU race
+        // between exists-check and open when another thread may delete concurrently.
+        return new BufferedInputStream(Files.newInputStream(filePath));
+    }
+
+    /**
+     * Store data from an InputStream as a file and return its unique ID and byte count. Streams
+     * directly to disk without buffering the entire content in heap.
+     *
+     * @param inputStream The input stream to read from
+     * @param originalName The original name of the file (unused, kept for API symmetry)
+     * @return A {@link StoredFile} containing the file ID and the number of bytes written
+     * @throws IOException If there is an error storing the file
+     */
+    public StoredFile storeInputStream(InputStream inputStream, String originalName)
+            throws IOException {
+        String fileId = generateFileId();
+        Path filePath = getFilePath(fileId);
+        Files.createDirectories(filePath.getParent());
+        long size = Files.copy(inputStream, filePath);
+        log.debug("Stored input stream with ID: {}", fileId);
+        return new StoredFile(fileId, size);
+    }
+
     /**
      * Delete a file by its ID
      *

app/common/src/main/java/stirling/software/common/service/JobExecutorService.java

@@ -316,7 +316,7 @@ public class JobExecutorService {
                             filename =
                                     disposition.substring(
                                             disposition.indexOf("filename=") + 9,
-                                            disposition.lastIndexOf("\""));
+                                            disposition.lastIndexOf('"'));
                         }
                     }
 

app/common/src/main/java/stirling/software/common/service/MobileScannerService.java

@@ -129,7 +129,7 @@ public class MobileScannerService {
                         FILE_EXTENSION_PATTERN.matcher(safeFilename).replaceFirst("");
                 String ext =
                         safeFilename.contains(".")
-                                ? safeFilename.substring(safeFilename.lastIndexOf("."))
+                                ? safeFilename.substring(safeFilename.lastIndexOf('.'))
                                 : "";
                 safeFilename = nameWithoutExt + "-" + counter + ext;
                 filePath = sessionDir.resolve(safeFilename).normalize().toAbsolutePath();

app/common/src/main/java/stirling/software/common/service/TaskManager.java

@@ -1,8 +1,8 @@
 package stirling.software.common.service;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
+import java.io.BufferedInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.time.LocalDateTime;
 import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
@@ -19,7 +19,6 @@ import java.util.zip.ZipInputStream;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Service;
-import org.springframework.web.multipart.MultipartFile;
 
 import io.github.pixee.security.ZipSecurity;
 
@@ -363,39 +362,29 @@ public class TaskManager {
             String zipFileId, String originalZipFileName) throws IOException {
         List<ResultFile> extractedFiles = new ArrayList<>();
 
-        MultipartFile zipFile = fileStorage.retrieveFile(zipFileId);
-
-        try (ZipInputStream zipIn =
-                ZipSecurity.createHardenedInputStream(
-                        new ByteArrayInputStream(zipFile.getBytes()))) {
+        try (InputStream fileStream = fileStorage.retrieveInputStream(zipFileId);
+                ZipInputStream zipIn =
+                        ZipSecurity.createHardenedInputStream(
+                                new BufferedInputStream(fileStream))) {
             ZipEntry entry;
             while ((entry = zipIn.getNextEntry()) != null) {
                 if (!entry.isDirectory()) {
-                    // Use buffered reading for memory safety
-                    ByteArrayOutputStream out = new ByteArrayOutputStream();
-                    byte[] buffer = new byte[4096];
-                    int bytesRead;
-                    while ((bytesRead = zipIn.read(buffer)) != -1) {
-                        out.write(buffer, 0, bytesRead);
-                    }
-                    byte[] fileContent = out.toByteArray();
-
                     String contentType = determineContentType(entry.getName());
-                    String individualFileId = fileStorage.storeBytes(fileContent, entry.getName());
+                    // storeInputStream returns the fileId and byte count — no extra stat needed
+                    FileStorage.StoredFile stored =
+                            fileStorage.storeInputStream(zipIn, entry.getName());
 
                     ResultFile resultFile =
                             ResultFile.builder()
-                                    .fileId(individualFileId)
+                                    .fileId(stored.fileId())
                                     .fileName(entry.getName())
                                     .contentType(contentType)
-                                    .fileSize(fileContent.length)
+                                    .fileSize(stored.size())
                                     .build();
 
                     extractedFiles.add(resultFile);
                     log.debug(
-                            "Extracted file: {} (size: {} bytes)",
-                            entry.getName(),
-                            fileContent.length);
+                            "Extracted file: {} (size: {} bytes)", entry.getName(), stored.size());
                 }
                 zipIn.closeEntry();
             }

app/common/src/main/java/stirling/software/common/util/CbzUtils.java

@@ -4,6 +4,7 @@ import java.io.BufferedInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.Enumeration;
@@ -30,15 +31,7 @@ import stirling.software.common.service.CustomPDFDocumentFactory;
 @UtilityClass
 public class CbzUtils {
 
-    public byte[] convertCbzToPdf(
-            MultipartFile cbzFile,
-            CustomPDFDocumentFactory pdfDocumentFactory,
-            TempFileManager tempFileManager)
-            throws IOException {
-        return convertCbzToPdf(cbzFile, pdfDocumentFactory, tempFileManager, false);
-    }
-
-    public byte[] convertCbzToPdf(
+    public TempFile convertCbzToPdf(
             MultipartFile cbzFile,
             CustomPDFDocumentFactory pdfDocumentFactory,
             TempFileManager tempFileManager,
@@ -64,70 +57,90 @@ public class CbzUtils {
 
             try (PDDocument document = pdfDocumentFactory.createNewDocument();
                     ZipFile zipFile = new ZipFile(tempFile.getFile())) {
+
+                // Pass 1: collect sorted image names (cheap just strings, no image data)
+                List<String> sortedImageNames = new ArrayList<>();
                 Enumeration<? extends ZipEntry> entries = zipFile.entries();
-                List<ImageEntryData> imageEntries = new ArrayList<>();
                 while (entries.hasMoreElements()) {
                     ZipEntry entry = entries.nextElement();
                     if (!entry.isDirectory() && isImageFile(entry.getName())) {
-                        try (InputStream is = zipFile.getInputStream(entry)) {
-                            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                            is.transferTo(baos);
-                            imageEntries.add(
-                                    new ImageEntryData(entry.getName(), baos.toByteArray()));
-                        } catch (IOException e) {
-                            log.warn("Error reading image {}: {}", entry.getName(), e.getMessage());
-                        }
+                        sortedImageNames.add(entry.getName());
                     }
                 }
+                sortedImageNames.sort(new NaturalOrderComparator());
 
-                imageEntries.sort(
-                        Comparator.comparing(ImageEntryData::name, new NaturalOrderComparator()));
-
-                if (imageEntries.isEmpty()) {
+                if (sortedImageNames.isEmpty()) {
                     throw ExceptionUtils.createCbzNoImagesException();
                 }
 
-                for (ImageEntryData imageEntry : imageEntries) {
-                    try {
-                        PDImageXObject pdImage =
-                                PDImageXObject.createFromByteArray(
-                                        document, imageEntry.data(), imageEntry.name());
-                        PDPage page =
-                                new PDPage(
-                                        new PDRectangle(pdImage.getWidth(), pdImage.getHeight()));
-                        document.addPage(page);
-                        try (PDPageContentStream contentStream =
-                                new PDPageContentStream(
-                                        document,
-                                        page,
-                                        PDPageContentStream.AppendMode.OVERWRITE,
-                                        true,
-                                        true)) {
-                            contentStream.drawImage(pdImage, 0, 0);
+                // Pass 2: load ONE image at a time peak memory = max(single image)
+                for (String imageName : sortedImageNames) {
+                    ZipEntry entry = zipFile.getEntry(imageName);
+                    try (InputStream is = zipFile.getInputStream(entry)) {
+                        ByteArrayOutputStream imgBaos = new ByteArrayOutputStream();
+                        is.transferTo(imgBaos);
+                        byte[] imageBytes = imgBaos.toByteArray();
+                        try {
+                            PDImageXObject pdImage =
+                                    PDImageXObject.createFromByteArray(
+                                            document, imageBytes, imageName);
+                            PDPage page =
+                                    new PDPage(
+                                            new PDRectangle(
+                                                    pdImage.getWidth(), pdImage.getHeight()));
+                            document.addPage(page);
+                            try (PDPageContentStream contentStream =
+                                    new PDPageContentStream(
+                                            document,
+                                            page,
+                                            PDPageContentStream.AppendMode.OVERWRITE,
+                                            true,
+                                            true)) {
+                                contentStream.drawImage(pdImage, 0, 0);
+                            }
+                        } catch (IOException e) {
+                            log.warn("Error processing image {}: {}", imageName, e.getMessage());
                         }
+                        // imageBytes eligible for GC after each iteration
                     } catch (IOException e) {
-                        log.warn(
-                                "Error processing image {}: {}", imageEntry.name(), e.getMessage());
+                        log.warn("Error reading image {}: {}", imageName, e.getMessage());
                     }
                 }
 
                 if (document.getNumberOfPages() == 0) {
                     throw ExceptionUtils.createCbzCorruptedImagesException();
                 }
-                ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                document.save(baos);
-                byte[] pdfBytes = baos.toByteArray();
 
-                // Apply Ghostscript optimization if requested
-                if (optimizeForEbook) {
-                    try {
-                        return GeneralUtils.optimizePdfWithGhostscript(pdfBytes);
-                    } catch (IOException e) {
-                        log.warn("Ghostscript optimization failed, returning unoptimized PDF", e);
+                // Write to TempFile (not BAOS)
+                TempFile pdfTempFile = new TempFile(tempFileManager, ".pdf");
+                try {
+                    document.save(pdfTempFile.getFile());
+
+                    if (optimizeForEbook) {
+                        try {
+                            byte[] pdfBytes = Files.readAllBytes(pdfTempFile.getPath());
+                            byte[] optimized = GeneralUtils.optimizePdfWithGhostscript(pdfBytes);
+                            pdfTempFile.close();
+                            TempFile optimizedFile = new TempFile(tempFileManager, ".pdf");
+                            try {
+                                Files.write(optimizedFile.getPath(), optimized);
+                                return optimizedFile;
+                            } catch (Exception e) {
+                                optimizedFile.close();
+                                throw e;
+                            }
+                        } catch (IOException e) {
+                            log.warn(
+                                    "Ghostscript optimization failed, returning unoptimized PDF",
+                                    e);
+                        }
                     }
-                }
 
-                return pdfBytes;
+                    return pdfTempFile;
+                } catch (Exception e) {
+                    pdfTempFile.close();
+                    throw e;
+                }
             }
         }
     }
@@ -175,8 +188,6 @@ public class CbzUtils {
         return RegexPatternUtils.getInstance().getImageFilePattern().matcher(filename).matches();
     }
 
-    private record ImageEntryData(String name, byte[] data) {}
-
     private class NaturalOrderComparator implements Comparator<String> {
         @Override
         public int compare(String s1, String s2) {

app/common/src/main/java/stirling/software/common/util/FileToPdf.java

@@ -44,9 +44,7 @@ public class FileToPdf {
                             sanitizeHtmlContent(
                                     new String(fileBytes, StandardCharsets.UTF_8),
                                     customHtmlSanitizer);
-                    Files.write(
-                            tempInputFile.getPath(),
-                            sanitizedHtml.getBytes(StandardCharsets.UTF_8));
+                    Files.writeString(tempInputFile.getPath(), sanitizedHtml);
                 } else if (fileName.toLowerCase(Locale.ROOT).endsWith(".zip")) {
                     Files.write(tempInputFile.getPath(), fileBytes);
                     sanitizeHtmlFilesInZip(
@@ -115,8 +113,7 @@ public class FileToPdf {
                                     new String(zipIn.readAllBytes(), StandardCharsets.UTF_8);
                             String sanitizedContent =
                                     sanitizeHtmlContent(content, customHtmlSanitizer);
-                            Files.write(
-                                    filePath, sanitizedContent.getBytes(StandardCharsets.UTF_8));
+                            Files.writeString(filePath, sanitizedContent);
                         } else {
                             Files.copy(zipIn, filePath);
                         }

app/common/src/main/java/stirling/software/common/util/FormUtils.java

@@ -17,6 +17,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.regex.Pattern;
 
 import org.apache.pdfbox.cos.COSArray;
 import org.apache.pdfbox.cos.COSBase;
@@ -74,6 +75,10 @@ public class FormUtils {
      */
     private static final float SAME_LINE_THRESHOLD_PT = 10.0f;
 
+    private static final Pattern HEX_UUID_PATTERN =
+            Pattern.compile("^[0-9a-fA-F]{8}[0-9a-fA-F]{24,}$");
+    private static final Pattern WHITESPACE_PATTERN = Pattern.compile("\\s+");
+
     /**
      * Returns a normalized logical type string for the supplied PDFBox field instance. Centralized
      * so all callers share identical mapping logic.
@@ -1357,7 +1362,7 @@ public class FormUtils {
             if (da != null && !da.isBlank()) {
                 // Standard DA looks like: /Helv 12 Tf 0 g
                 // We want the number before 'Tf'
-                String[] tokens = da.split("\\s+");
+                String[] tokens = WHITESPACE_PATTERN.split(da);
                 for (int i = 0; i < tokens.length; i++) {
                     if ("Tf".equals(tokens[i]) && i > 0) {
                         try {
@@ -1457,9 +1462,8 @@ public class FormUtils {
         // Detect UUID-like hex strings (e.g. "cdc47b7041524571 7b2d93017fe77bf7")
         // Standard UUIDs are 32 hex characters; require at least that to avoid
         // false positives on short hex-like field names.
-        String nospaces = simplified.replaceAll("\\s+", "");
-        if (nospaces.length() >= 32 && nospaces.matches("^[0-9a-fA-F]{8}[0-9a-fA-F]{24,}$"))
-            return true;
+        String nospaces = WHITESPACE_PATTERN.matcher(simplified).replaceAll("");
+        if (nospaces.length() >= 32 && HEX_UUID_PATTERN.matcher(nospaces).matches()) return true;
 
         return patterns.getGenericFieldNamePattern().matcher(simplified).matches()
                 || patterns.getSimpleFormFieldPattern().matcher(simplified).matches()

app/common/src/main/java/stirling/software/common/util/PDFToFile.java

@@ -10,6 +10,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
+import java.util.regex.Pattern;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -33,6 +34,8 @@ import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
 @Slf4j
 public class PDFToFile {
 
+    private static final Pattern PATTERN =
+            Pattern.compile("(!\\[.*?\\])\\((?!images/)([^/)][^)]*?)\\)");
     private final TempFileManager tempFileManager;
     private final RuntimePathConfig runtimePathConfig;
 
@@ -163,7 +166,7 @@ public class PDFToFile {
     private String updateImageReferences(String markdown) {
         // Match markdown image syntax: ![alt text](image.png)
         // Only update if the path doesn't already start with images/
-        return markdown.replaceAll("(!\\[.*?\\])\\((?!images/)([^/)][^)]*?)\\)", "$1(images/$2)");
+        return PATTERN.matcher(markdown).replaceAll("$1(images/$2)");
     }
 
     public ResponseEntity<byte[]> processPdfToHtml(MultipartFile inputFile)

app/common/src/main/java/stirling/software/common/util/PdfToCbzUtils.java

@@ -1,8 +1,8 @@
 package stirling.software.common.util;
 
 import java.awt.image.BufferedImage;
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.util.Locale;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
@@ -22,8 +22,11 @@ import stirling.software.common.service.CustomPDFDocumentFactory;
 @Slf4j
 public class PdfToCbzUtils {
 
-    public static byte[] convertPdfToCbz(
-            MultipartFile pdfFile, int dpi, CustomPDFDocumentFactory pdfDocumentFactory)
+    public static TempFile convertPdfToCbz(
+            MultipartFile pdfFile,
+            int dpi,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager)
             throws IOException {
 
         validatePdfFile(pdfFile);
@@ -33,7 +36,7 @@ public class PdfToCbzUtils {
                 throw ExceptionUtils.createPdfNoPages();
             }
 
-            return createCbzFromPdf(document, dpi);
+            return createCbzFromPdf(document, dpi, tempFileManager);
         }
     }
 
@@ -53,46 +56,49 @@ public class PdfToCbzUtils {
         }
     }
 
-    private static byte[] createCbzFromPdf(PDDocument document, int dpi) throws IOException {
+    private static TempFile createCbzFromPdf(
+            PDDocument document, int dpi, TempFileManager tempFileManager) throws IOException {
         PDFRenderer pdfRenderer = new PDFRenderer(document);
         pdfRenderer.setSubsamplingAllowed(true); // Enable subsampling to reduce memory usage
 
-        try (ByteArrayOutputStream cbzOutputStream = new ByteArrayOutputStream();
-                ZipOutputStream zipOut = new ZipOutputStream(cbzOutputStream)) {
+        TempFile cbzTempFile = new TempFile(tempFileManager, ".cbz");
+        try {
+            try (ZipOutputStream zipOut =
+                    new ZipOutputStream(Files.newOutputStream(cbzTempFile.getPath()))) {
 
-            int totalPages = document.getNumberOfPages();
+                int totalPages = document.getNumberOfPages();
 
-            for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
-                final int currentPage = pageIndex;
-                try {
-                    BufferedImage image =
-                            ExceptionUtils.handleOomRendering(
-                                    currentPage + 1,
-                                    dpi,
-                                    () ->
-                                            pdfRenderer.renderImageWithDPI(
-                                                    currentPage, dpi, ImageType.RGB));
+                for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+                    final int currentPage = pageIndex;
+                    try {
+                        BufferedImage image =
+                                ExceptionUtils.handleOomRendering(
+                                        currentPage + 1,
+                                        dpi,
+                                        () ->
+                                                pdfRenderer.renderImageWithDPI(
+                                                        currentPage, dpi, ImageType.RGB));
 
-                    String imageFilename =
-                            String.format(Locale.ROOT, "page_%03d.png", currentPage + 1);
-                    ZipEntry zipEntry = new ZipEntry(imageFilename);
-                    zipOut.putNextEntry(zipEntry);
+                        String imageFilename =
+                                String.format(Locale.ROOT, "page_%03d.png", currentPage + 1);
+                        zipOut.putNextEntry(new ZipEntry(imageFilename));
+                        ImageIO.write(image, "PNG", zipOut);
+                        zipOut.closeEntry();
 
-                    ImageIO.write(image, "PNG", zipOut);
-                    zipOut.closeEntry();
-
-                } catch (ExceptionUtils.OutOfMemoryDpiException e) {
-                    // Re-throw OOM exceptions without wrapping
-                    throw e;
-                } catch (IOException e) {
-                    // Wrap other IOExceptions with context
-                    throw ExceptionUtils.createFileProcessingException(
-                            "CBZ creation for page " + (currentPage + 1), e);
+                    } catch (ExceptionUtils.OutOfMemoryDpiException e) {
+                        // Re-throw OOM exceptions without wrapping
+                        throw e;
+                    } catch (IOException e) {
+                        // Wrap other IOExceptions with context
+                        throw ExceptionUtils.createFileProcessingException(
+                                "CBZ creation for page " + (currentPage + 1), e);
+                    }
                 }
             }
-
-            zipOut.finish();
-            return cbzOutputStream.toByteArray();
+            return cbzTempFile;
+        } catch (Exception e) {
+            cbzTempFile.close();
+            throw e;
         }
     }
 

app/common/src/main/java/stirling/software/common/util/PdfUtils.java

@@ -219,58 +219,31 @@ public class PdfUtils {
                     int maxWidth = 0;
                     int totalHeight = 0;
 
-                    BufferedImage pdfSizeImage = null;
-                    int pdfSizeImageIndex = -1;
-
-                    // Using a map to store the rendered dimensions of each page size
-                    // to avoid rendering the same page sizes multiple times
+                    // Using a map to store the calculated dimensions of each page size
                     HashMap<PdfRenderSettingsKey, PdfImageDimensionValue> pageSizes =
                             new HashMap<>();
                     for (int i = 0; i < pageCount; ++i) {
-                        final int pageIndex = i;
                         PDPage page = document.getPage(i);
-                        PDRectangle mediaBox = page.getMediaBox();
+                        PDRectangle cropBox = page.getCropBox();
                         int rotation = page.getRotation();
                         PdfRenderSettingsKey settings =
                                 new PdfRenderSettingsKey(
-                                        mediaBox.getWidth(), mediaBox.getHeight(), rotation);
+                                        cropBox.getWidth(), cropBox.getHeight(), rotation);
                         PdfImageDimensionValue dimension = pageSizes.get(settings);
                         if (dimension == null) {
-                            // Render the image to get the dimensions
-                            try {
-                                // Validate dimensions before rendering
-                                ExceptionUtils.validateRenderingDimensions(
-                                        page, pageIndex + 1, DPI);
-
-                                pdfSizeImage =
-                                        ExceptionUtils.handleOomRendering(
-                                                pageIndex + 1,
-                                                DPI,
-                                                () ->
-                                                        pdfRenderer.renderImageWithDPI(
-                                                                pageIndex, DPI, colorType));
-                            } catch (IllegalArgumentException e) {
-                                if (e.getMessage() != null
-                                        && e.getMessage()
-                                                .contains("Maximum size of image exceeded")) {
-                                    throw ExceptionUtils.createIllegalArgumentException(
-                                            "error.pageTooBigExceedsArray",
-                                            "PDF page {0} is too large to render at {1} DPI. The"
-                                                    + " resulting image would exceed Java's maximum"
-                                                    + " array size. Please try a lower DPI value"
-                                                    + " (recommended: 150 or less).",
-                                            i + 1,
-                                            DPI);
-                                }
-                                throw e;
+                            float scale = DPI / 72f;
+                            int widthPx = (int) Math.max(Math.floor(cropBox.getWidth() * scale), 1);
+                            int heightPx =
+                                    (int) Math.max(Math.floor(cropBox.getHeight() * scale), 1);
+                            if (rotation == 90 || rotation == 270) {
+                                int tmp = widthPx;
+                                widthPx = heightPx;
+                                heightPx = tmp;
                             }
-                            pdfSizeImageIndex = i;
-                            dimension =
-                                    new PdfImageDimensionValue(
-                                            pdfSizeImage.getWidth(), pdfSizeImage.getHeight());
+                            dimension = new PdfImageDimensionValue(widthPx, heightPx);
                             pageSizes.put(settings, dimension);
-                            if (pdfSizeImage.getWidth() > maxWidth) {
-                                maxWidth = pdfSizeImage.getWidth();
+                            if (widthPx > maxWidth) {
+                                maxWidth = widthPx;
                             }
                         }
                         totalHeight += dimension.height();
@@ -284,40 +257,32 @@ public class PdfUtils {
                     int currentHeight = 0;
                     BufferedImage pageImage;
 
-                    // Check if the first image is the last rendered image
-                    boolean firstImageAlreadyRendered = pdfSizeImageIndex == 0;
-
                     for (int i = 0; i < pageCount; ++i) {
                         final int pageIndex = i;
-                        if (firstImageAlreadyRendered && i == 0) {
-                            pageImage = pdfSizeImage;
-                        } else {
-                            try {
-                                // Validate dimensions before rendering
-                                ExceptionUtils.validateRenderingDimensions(
-                                        document.getPage(pageIndex), pageIndex + 1, DPI);
+                        try {
+                            // Validate dimensions before rendering
+                            ExceptionUtils.validateRenderingDimensions(
+                                    document.getPage(pageIndex), pageIndex + 1, DPI);
 
-                                pageImage =
-                                        ExceptionUtils.handleOomRendering(
-                                                pageIndex + 1,
-                                                DPI,
-                                                () ->
-                                                        pdfRenderer.renderImageWithDPI(
-                                                                pageIndex, DPI, colorType));
-                            } catch (IllegalArgumentException e) {
-                                if (e.getMessage() != null
-                                        && e.getMessage()
-                                                .contains("Maximum size of image exceeded")) {
-                                    throw ExceptionUtils.createIllegalArgumentException(
-                                            "error.pageTooBigForDpi",
-                                            "PDF page {0} is too large to render at {1} DPI. Please"
-                                                    + " try a lower DPI value (recommended: 150 or"
-                                                    + " less).",
-                                            i + 1,
-                                            DPI);
-                                }
-                                throw e;
+                            pageImage =
+                                    ExceptionUtils.handleOomRendering(
+                                            pageIndex + 1,
+                                            DPI,
+                                            () ->
+                                                    pdfRenderer.renderImageWithDPI(
+                                                            pageIndex, DPI, colorType));
+                        } catch (IllegalArgumentException e) {
+                            if (e.getMessage() != null
+                                    && e.getMessage().contains("Maximum size of image exceeded")) {
+                                throw ExceptionUtils.createIllegalArgumentException(
+                                        "error.pageTooBigForDpi",
+                                        "PDF page {0} is too large to render at {1} DPI. Please"
+                                                + " try a lower DPI value (recommended: 150 or"
+                                                + " less).",
+                                        i + 1,
+                                        DPI);
                             }
+                            throw e;
                         }
 
                         // Calculate the x-coordinate to center the image

app/common/src/main/java/stirling/software/common/util/YamlHelper.java

@@ -191,7 +191,7 @@ public class YamlHelper {
             mappingNode.getValue().clear();
             mappingNode.getValue().addAll(updatedTuples);
         }
-        setNewNode(node);
+        updatedRootNode = node;
 
         return updated;
     }

app/common/src/main/java/stirling/software/common/util/misc/ReplaceAndInvertColorStrategy.java

@@ -19,7 +19,7 @@ public abstract class ReplaceAndInvertColorStrategy extends PDFFile {
 
     public ReplaceAndInvertColorStrategy(MultipartFile file, ReplaceAndInvert replaceAndInvert) {
         setFileInput(file);
-        setReplaceAndInvert(replaceAndInvert);
+        this.replaceAndInvert = replaceAndInvert;
     }
 
     public abstract InputStreamResource replace() throws IOException;

app/core/src/main/java/org/apache/pdfbox/examples/signature/CreateSignatureBase.java

@@ -88,10 +88,10 @@ public abstract class CreateSignatureBase implements SignatureInterface {
         Certificate cert = null;
         while (cert == null && aliases.hasMoreElements()) {
             alias = aliases.nextElement();
-            setPrivateKey((PrivateKey) keystore.getKey(alias, pin));
+            privateKey = (PrivateKey) keystore.getKey(alias, pin);
             Certificate[] certChain = keystore.getCertificateChain(alias);
             if (certChain != null) {
-                setCertificateChain(certChain);
+                certificateChain = certChain;
                 cert = certChain[0];
                 if (cert instanceof X509Certificate) {
                     // avoid expired certificate

app/core/src/main/java/stirling/software/SPDF/SPDFApplication.java

@@ -134,7 +134,7 @@ public class SPDFApplication {
         baseUrlStatic = normalizeBackendUrl(backendUrl, serverPort);
         contextPathStatic = contextPath;
         serverPortStatic = serverPort;
-        String url = buildFullUrl(baseUrlStatic, getStaticPort(), contextPathStatic);
+        String url = buildFullUrl(baseUrlStatic, serverPortStatic, contextPathStatic);
 
         // Log Tauri mode information
         if (Boolean.parseBoolean(System.getProperty("STIRLING_PDF_TAURI_MODE", "false"))) {
@@ -188,7 +188,7 @@ public class SPDFApplication {
 
     private static void printStartupLogs() {
         log.info("Stirling-PDF Started.");
-        String url = buildFullUrl(baseUrlStatic, getStaticPort(), contextPathStatic);
+        String url = buildFullUrl(baseUrlStatic, serverPortStatic, contextPathStatic);
         log.info("Navigate to {}", url);
     }
 

app/core/src/main/java/stirling/software/SPDF/config/EndpointInspector.java

@@ -104,7 +104,7 @@ public class EndpointInspector implements ApplicationListener<ContextRefreshedEv
             String infoString = mappingInfo.toString();
             if (infoString.contains("{")) {
                 String patternsSection =
-                        infoString.substring(infoString.indexOf("{") + 1, infoString.indexOf("}"));
+                        infoString.substring(infoString.indexOf('{') + 1, infoString.indexOf('}'));
 
                 for (String pattern : patternsSection.split(",")) {
                     pattern = pattern.trim();

app/core/src/main/java/stirling/software/SPDF/controller/api/PosterPdfController.java

@@ -1,7 +1,7 @@
 package stirling.software.SPDF.controller.api;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.zip.ZipEntry;
@@ -14,10 +14,10 @@ import org.apache.pdfbox.pdmodel.PDPageContentStream;
 import org.apache.pdfbox.pdmodel.common.PDRectangle;
 import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
 import org.apache.pdfbox.util.Matrix;
-import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -31,6 +31,8 @@ import stirling.software.common.annotations.api.GeneralApi;
 import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.util.ExceptionUtils;
 import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
 
 @GeneralApi
@@ -39,10 +41,9 @@ import stirling.software.common.util.WebResponseUtils;
 public class PosterPdfController {
 
     private final CustomPDFDocumentFactory pdfDocumentFactory;
+    private final TempFileManager tempFileManager;
 
-    @AutoJobPostMapping(
-            value = "/split-for-poster-print",
-            consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
+    @AutoJobPostMapping(value = "/split-for-poster-print", consumes = "multipart/form-data")
     @MultiFileResponse
     @Operation(
             summary = "Split large PDF pages into smaller printable chunks",
@@ -51,7 +52,7 @@ public class PosterPdfController {
                             + "suitable for printing on standard paper sizes (e.g., A4, Letter). "
                             + "Divides each page into a grid of smaller pages using Apache PDFBox. "
                             + "Input: PDF Output: ZIP-PDF Type: SISO")
-    public ResponseEntity<byte[]> posterPdf(@ModelAttribute PosterPdfRequest request)
+    public ResponseEntity<StreamingResponseBody> posterPdf(@ModelAttribute PosterPdfRequest request)
             throws Exception {
 
         log.debug("Starting PDF poster split process with request: {}", request);
@@ -60,184 +61,187 @@ public class PosterPdfController {
         String filename = GeneralUtils.generateFilename(file.getOriginalFilename(), "");
         log.debug("Base filename for output: {}", filename);
 
-        try (PDDocument sourceDocument = pdfDocumentFactory.load(file);
-                PDDocument outputDocument =
-                        pdfDocumentFactory.createNewDocumentBasedOnOldDocument(sourceDocument);
-                ByteArrayOutputStream pdfOutputStream = new ByteArrayOutputStream();
-                ByteArrayOutputStream zipOutputStream = new ByteArrayOutputStream()) {
+        TempFile zipTempFile = new TempFile(tempFileManager, ".zip");
+        try {
+            try (PDDocument sourceDocument = pdfDocumentFactory.load(file);
+                    PDDocument outputDocument =
+                            pdfDocumentFactory.createNewDocumentBasedOnOldDocument(sourceDocument);
+                    TempFile pdfTempFile = new TempFile(tempFileManager, ".pdf")) {
 
-            // Get target page size
-            PDRectangle targetPageSize = getTargetPageSize(request.getPageSize());
-            log.debug(
-                    "Target page size: {} ({}x{})",
-                    request.getPageSize(),
-                    targetPageSize.getWidth(),
-                    targetPageSize.getHeight());
+                // Get target page size
+                PDRectangle targetPageSize = getTargetPageSize(request.getPageSize());
+                log.debug(
+                        "Target page size: {} ({}x{})",
+                        request.getPageSize(),
+                        targetPageSize.getWidth(),
+                        targetPageSize.getHeight());
 
-            // Create LayerUtility for importing pages as forms
-            LayerUtility layerUtility = new LayerUtility(outputDocument);
+                // Create LayerUtility for importing pages as forms
+                LayerUtility layerUtility = new LayerUtility(outputDocument);
 
-            int totalPages = sourceDocument.getNumberOfPages();
-            int xFactor = request.getXFactor();
-            int yFactor = request.getYFactor();
-            boolean rightToLeft = request.isRightToLeft();
-
-            log.debug(
-                    "Processing {} pages with grid {}x{}, RTL={}",
-                    totalPages,
-                    xFactor,
-                    yFactor,
-                    rightToLeft);
-
-            // Process each page
-            for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
-                PDPage sourcePage = sourceDocument.getPage(pageIndex);
-
-                // Get both MediaBox and CropBox
-                PDRectangle mediaBox = sourcePage.getMediaBox();
-                PDRectangle cropBox = sourcePage.getCropBox();
-
-                // If no CropBox is set, use MediaBox
-                if (cropBox == null) {
-                    cropBox = mediaBox;
-                }
-
-                // Save original boxes for restoration
-                PDRectangle originalMediaBox = sourcePage.getMediaBox();
-                PDRectangle originalCropBox = sourcePage.getCropBox();
-
-                // Normalize the page: set MediaBox to CropBox
-                // This ensures the form's coordinate space starts at (0, 0)
-                // instead of having an offset from the original MediaBox
-                sourcePage.setMediaBox(cropBox);
-                sourcePage.setCropBox(cropBox);
-
-                // Handle page rotation
-                int rotation = sourcePage.getRotation();
-                float sourceWidth = cropBox.getWidth();
-                float sourceHeight = cropBox.getHeight();
-
-                // Swap dimensions if rotated 90 or 270 degrees
-                if (rotation == 90 || rotation == 270) {
-                    float temp = sourceWidth;
-                    sourceWidth = sourceHeight;
-                    sourceHeight = temp;
-                }
+                int totalPages = sourceDocument.getNumberOfPages();
+                int xFactor = request.getXFactor();
+                int yFactor = request.getYFactor();
+                boolean rightToLeft = request.isRightToLeft();
 
                 log.debug(
-                        "Page {}: Normalized to CropBox dimensions {}x{}, rotation {}",
-                        pageIndex,
-                        sourceWidth,
-                        sourceHeight,
-                        rotation);
+                        "Processing {} pages with grid {}x{}, RTL={}",
+                        totalPages,
+                        xFactor,
+                        yFactor,
+                        rightToLeft);
 
-                // Import source page as form (now with normalized coordinate space)
-                PDFormXObject form = layerUtility.importPageAsForm(sourceDocument, pageIndex);
+                // Process each page
+                for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+                    PDPage sourcePage = sourceDocument.getPage(pageIndex);
 
-                // Restore original boxes
-                sourcePage.setMediaBox(originalMediaBox);
-                sourcePage.setCropBox(originalCropBox);
+                    // Get both MediaBox and CropBox
+                    PDRectangle mediaBox = sourcePage.getMediaBox();
+                    PDRectangle cropBox = sourcePage.getCropBox();
 
-                // Calculate cell dimensions in source page coordinates
-                float cellWidth = sourceWidth / xFactor;
-                float cellHeight = sourceHeight / yFactor;
+                    // If no CropBox is set, use MediaBox
+                    if (cropBox == null) {
+                        cropBox = mediaBox;
+                    }
 
-                // Create grid cells (rows × columns)
-                for (int row = 0; row < yFactor; row++) {
-                    for (int col = 0; col < xFactor; col++) {
-                        // Apply RTL ordering for columns if enabled
-                        int actualCol = rightToLeft ? (xFactor - 1 - col) : col;
+                    // Save original boxes for restoration
+                    PDRectangle originalMediaBox = sourcePage.getMediaBox();
+                    PDRectangle originalCropBox = sourcePage.getCropBox();
 
-                        // Calculate crop rectangle in source coordinates
-                        // PDF coordinates start at bottom-left
-                        float cropX = actualCol * cellWidth;
-                        // For Y: invert so row 0 shows TOP (following SplitPdfBySectionsController
-                        // pattern)
-                        float cropY = (yFactor - 1 - row) * cellHeight;
+                    // Normalize the page: set MediaBox to CropBox
+                    // This ensures the form's coordinate space starts at (0, 0)
+                    // instead of having an offset from the original MediaBox
+                    sourcePage.setMediaBox(cropBox);
+                    sourcePage.setCropBox(cropBox);
 
-                        // Create new output page with target size
-                        PDPage outputPage = new PDPage(targetPageSize);
-                        outputDocument.addPage(outputPage);
+                    // Handle page rotation
+                    int rotation = sourcePage.getRotation();
+                    float sourceWidth = cropBox.getWidth();
+                    float sourceHeight = cropBox.getHeight();
 
-                        try (PDPageContentStream contentStream =
-                                new PDPageContentStream(
-                                        outputDocument,
-                                        outputPage,
-                                        PDPageContentStream.AppendMode.APPEND,
-                                        true,
-                                        true)) {
+                    // Swap dimensions if rotated 90 or 270 degrees
+                    if (rotation == 90 || rotation == 270) {
+                        float temp = sourceWidth;
+                        sourceWidth = sourceHeight;
+                        sourceHeight = temp;
+                    }
 
-                            // Calculate uniform scale to fit cell into target page
-                            // Scale UP if cell is smaller than target, scale DOWN if larger
-                            float scaleX = targetPageSize.getWidth() / cellWidth;
-                            float scaleY = targetPageSize.getHeight() / cellHeight;
-                            float scale = Math.min(scaleX, scaleY);
+                    log.debug(
+                            "Page {}: Normalized to CropBox dimensions {}x{}, rotation {}",
+                            pageIndex,
+                            sourceWidth,
+                            sourceHeight,
+                            rotation);
 
-                            // Center the scaled content on the target page
-                            float scaledCellWidth = cellWidth * scale;
-                            float scaledCellHeight = cellHeight * scale;
-                            float offsetX = (targetPageSize.getWidth() - scaledCellWidth) / 2;
-                            float offsetY = (targetPageSize.getHeight() - scaledCellHeight) / 2;
+                    // Import source page as form (now with normalized coordinate space)
+                    PDFormXObject form = layerUtility.importPageAsForm(sourceDocument, pageIndex);
 
-                            // Apply transformations
-                            contentStream.saveGraphicsState();
+                    // Restore original boxes
+                    sourcePage.setMediaBox(originalMediaBox);
+                    sourcePage.setCropBox(originalCropBox);
 
-                            // Translate to center position
-                            contentStream.transform(Matrix.getTranslateInstance(offsetX, offsetY));
+                    // Calculate cell dimensions in source page coordinates
+                    float cellWidth = sourceWidth / xFactor;
+                    float cellHeight = sourceHeight / yFactor;
 
-                            // Scale uniformly
-                            contentStream.transform(Matrix.getScaleInstance(scale, scale));
+                    // Create grid cells (rows × columns)
+                    for (int row = 0; row < yFactor; row++) {
+                        for (int col = 0; col < xFactor; col++) {
+                            // Apply RTL ordering for columns if enabled
+                            int actualCol = rightToLeft ? (xFactor - 1 - col) : col;
 
-                            // Translate to show only the desired grid cell
-                            // IMPORTANT: The PDFormXObject's BBox already matches the CropBox
-                            // (including its offset), so we only need to translate by cropX/cropY
-                            // relative to the CropBox origin, NOT the MediaBox origin
-                            contentStream.transform(Matrix.getTranslateInstance(-cropX, -cropY));
+                            // Calculate crop rectangle in source coordinates
+                            // PDF coordinates start at bottom-left
+                            float cropX = actualCol * cellWidth;
+                            // For Y: invert so row 0 shows TOP (following
+                            // SplitPdfBySectionsController
+                            // pattern)
+                            float cropY = (yFactor - 1 - row) * cellHeight;
 
-                            // Draw the form
-                            contentStream.drawForm(form);
+                            // Create new output page with target size
+                            PDPage outputPage = new PDPage(targetPageSize);
+                            outputDocument.addPage(outputPage);
 
-                            contentStream.restoreGraphicsState();
+                            try (PDPageContentStream contentStream =
+                                    new PDPageContentStream(
+                                            outputDocument,
+                                            outputPage,
+                                            PDPageContentStream.AppendMode.APPEND,
+                                            true,
+                                            true)) {
+
+                                // Calculate uniform scale to fit cell into target page
+                                // Scale UP if cell is smaller than target, scale DOWN if larger
+                                float scaleX = targetPageSize.getWidth() / cellWidth;
+                                float scaleY = targetPageSize.getHeight() / cellHeight;
+                                float scale = Math.min(scaleX, scaleY);
+
+                                // Center the scaled content on the target page
+                                float scaledCellWidth = cellWidth * scale;
+                                float scaledCellHeight = cellHeight * scale;
+                                float offsetX = (targetPageSize.getWidth() - scaledCellWidth) / 2;
+                                float offsetY = (targetPageSize.getHeight() - scaledCellHeight) / 2;
+
+                                // Apply transformations
+                                contentStream.saveGraphicsState();
+
+                                // Translate to center position
+                                contentStream.transform(
+                                        Matrix.getTranslateInstance(offsetX, offsetY));
+
+                                // Scale uniformly
+                                contentStream.transform(Matrix.getScaleInstance(scale, scale));
+
+                                // Translate to show only the desired grid cell
+                                // IMPORTANT: The PDFormXObject's BBox already matches the CropBox
+                                // (including its offset), so we only need to translate by
+                                // cropX/cropY
+                                // relative to the CropBox origin, NOT the MediaBox origin
+                                contentStream.transform(
+                                        Matrix.getTranslateInstance(-cropX, -cropY));
+
+                                // Draw the form
+                                contentStream.drawForm(form);
+
+                                contentStream.restoreGraphicsState();
+                            }
+
+                            log.trace(
+                                    "Created output page for grid cell [{},{}] of page {}: cropX={}, cropY={}, translate=({}, {})",
+                                    row,
+                                    actualCol,
+                                    pageIndex,
+                                    cropX,
+                                    cropY,
+                                    -cropX,
+                                    -cropY);
                         }
-
-                        log.trace(
-                                "Created output page for grid cell [{},{}] of page {}: cropX={}, cropY={}, translate=({}, {})",
-                                row,
-                                actualCol,
-                                pageIndex,
-                                cropX,
-                                cropY,
-                                -cropX,
-                                -cropY);
                     }
                 }
+
+                // Save output PDF to intermediate TempFile
+                outputDocument.save(pdfTempFile.getFile());
+                log.debug("Generated output PDF with {} pages", outputDocument.getNumberOfPages());
+
+                // Create ZIP from the PDF TempFile, streaming directly to zip TempFile
+                try (ZipOutputStream zipOut =
+                        new ZipOutputStream(Files.newOutputStream(zipTempFile.getPath()))) {
+                    zipOut.putNextEntry(new ZipEntry(filename + "_poster.pdf"));
+                    Files.copy(pdfTempFile.getPath(), zipOut);
+                    zipOut.closeEntry();
+                }
+                // pdfTempFile auto-closed and deleted here (end of inner try-with-resources)
             }
 
-            // Save output PDF
-            outputDocument.save(pdfOutputStream);
-            byte[] pdfData = pdfOutputStream.toByteArray();
-
-            log.debug(
-                    "Generated output PDF with {} pages ({} bytes)",
-                    outputDocument.getNumberOfPages(),
-                    pdfData.length);
-
-            // Create ZIP file with the result
-            try (ZipOutputStream zipOut = new ZipOutputStream(zipOutputStream)) {
-                ZipEntry zipEntry = new ZipEntry(filename + "_poster.pdf");
-                zipOut.putNextEntry(zipEntry);
-                zipOut.write(pdfData);
-                zipOut.closeEntry();
-            }
-
-            byte[] zipData = zipOutputStream.toByteArray();
-            log.debug("Successfully created ZIP with {} bytes", zipData.length);
-
-            return WebResponseUtils.bytesToWebResponse(
-                    zipData, filename + "_poster.zip", MediaType.APPLICATION_OCTET_STREAM);
+            log.debug("Successfully created ZIP");
+            return WebResponseUtils.zipFileToWebResponse(zipTempFile, filename + "_poster.zip");
 
         } catch (IOException e) {
             ExceptionUtils.logException("PDF poster split process", e);
+            zipTempFile.close();
+            throw e;
+        } catch (Exception e) {
+            zipTempFile.close();
             throw e;
         }
     }

app/core/src/main/java/stirling/software/SPDF/controller/api/SplitPDFController.java

@@ -1,6 +1,5 @@
 package stirling.software.SPDF.controller.api;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.util.ArrayList;
@@ -10,11 +9,11 @@ import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
 import org.apache.pdfbox.pdmodel.PDDocument;
-import org.apache.pdfbox.pdmodel.PDPage;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -49,83 +48,60 @@ public class SplitPDFController {
                             + " specified page numbers or ranges. Users can specify pages using"
                             + " individual numbers, ranges, or 'all' for every page. Input:PDF"
                             + " Output:PDF Type:SIMO")
-    public ResponseEntity<byte[]> splitPdf(@ModelAttribute PDFWithPageNums request)
+    public ResponseEntity<StreamingResponseBody> splitPdf(@ModelAttribute PDFWithPageNums request)
             throws IOException {
 
         MultipartFile file = request.getFileInput();
-
-        try (TempFile outputTempFile = new TempFile(tempFileManager, ".zip");
-                PDDocument document = pdfDocumentFactory.load(file)) {
-
-            List<ByteArrayOutputStream> splitDocumentsBoas = new ArrayList<>();
-
-            int totalPages = document.getNumberOfPages();
-            List<Integer> pageNumbers = request.getPageNumbersList(document, false);
-            if (!pageNumbers.contains(totalPages - 1)) {
-                // Create a mutable ArrayList so we can add to it
-                pageNumbers = new ArrayList<>(pageNumbers);
-                pageNumbers.add(totalPages - 1);
-            }
-
-            log.debug(
-                    "Splitting PDF into pages: {}",
-                    pageNumbers.stream().map(String::valueOf).collect(Collectors.joining(",")));
-
-            splitDocumentsBoas = new ArrayList<>(pageNumbers.size());
-            int previousPageNumber = 0;
-            for (int splitPoint : pageNumbers) {
-                try (PDDocument splitDocument =
-                                pdfDocumentFactory.createNewDocumentBasedOnOldDocument(document);
-                        ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
-                    for (int i = previousPageNumber; i <= splitPoint; i++) {
-                        PDPage page = document.getPage(i);
-                        splitDocument.addPage(page);
-                        log.debug("Adding page {} to split document", i);
-                    }
-                    previousPageNumber = splitPoint + 1;
-
-                    // Transfer metadata to split pdf
-                    // PdfMetadataService.setMetadataToPdf(splitDocument, metadata);
-
-                    splitDocument.save(baos);
-                    splitDocumentsBoas.add(baos);
-                } catch (Exception e) {
-                    ExceptionUtils.logException("document splitting and saving", e);
-                    throw e;
+        TempFile outputTempFile = new TempFile(tempFileManager, ".zip");
+        try {
+            try (PDDocument document = pdfDocumentFactory.load(file)) {
+                int totalPages = document.getNumberOfPages();
+                List<Integer> pageNumbers = request.getPageNumbersList(document, false);
+                if (!pageNumbers.contains(totalPages - 1)) {
+                    pageNumbers = new ArrayList<>(pageNumbers);
+                    pageNumbers.add(totalPages - 1);
                 }
-            }
 
-            String baseFilename = GeneralUtils.removeExtension(file.getOriginalFilename());
+                log.debug(
+                        "Splitting PDF into pages: {}",
+                        pageNumbers.stream().map(String::valueOf).collect(Collectors.joining(",")));
 
-            try (ZipOutputStream zipOut =
-                    new ZipOutputStream(Files.newOutputStream(outputTempFile.getPath()))) {
-                int splitDocumentsSize = splitDocumentsBoas.size();
-                for (int i = 0; i < splitDocumentsSize; i++) {
-                    StringBuilder sb = new StringBuilder(baseFilename.length() + 10);
-                    sb.append(baseFilename).append('_').append(i + 1).append(".pdf");
-                    String fileName = sb.toString();
+                String baseFilename = GeneralUtils.removeExtension(file.getOriginalFilename());
+                try (ZipOutputStream zipOut =
+                        new ZipOutputStream(Files.newOutputStream(outputTempFile.getPath()))) {
+                    int previousPageNumber = 0;
+                    for (int splitIndex = 0; splitIndex < pageNumbers.size(); splitIndex++) {
+                        int splitPoint = pageNumbers.get(splitIndex);
+                        try (PDDocument splitDocument =
+                                pdfDocumentFactory.createNewDocumentBasedOnOldDocument(document)) {
+                            for (int i = previousPageNumber; i <= splitPoint; i++) {
+                                splitDocument.addPage(document.getPage(i));
+                                log.debug("Adding page {} to split document", i);
+                            }
+                            previousPageNumber = splitPoint + 1;
 
-                    ByteArrayOutputStream baos = splitDocumentsBoas.get(i);
-                    byte[] pdf = baos.toByteArray();
-
-                    ZipEntry pdfEntry = new ZipEntry(fileName);
-                    zipOut.putNextEntry(pdfEntry);
-                    zipOut.write(pdf);
-                    zipOut.closeEntry();
-
-                    log.debug("Wrote split document {} to zip file", fileName);
+                            String fileName = baseFilename + "_" + (splitIndex + 1) + ".pdf";
+                            zipOut.putNextEntry(new ZipEntry(fileName));
+                            splitDocument.save(zipOut);
+                            zipOut.closeEntry();
+                            log.debug("Wrote split document {} to zip file", fileName);
+                        } catch (Exception e) {
+                            ExceptionUtils.logException("document splitting and saving", e);
+                            throw e;
+                        }
+                    }
                 }
             }
 
             log.debug(
                     "Successfully created zip file with split documents: {}",
                     outputTempFile.getPath().toString());
-            byte[] data = Files.readAllBytes(outputTempFile.getPath());
-
             String zipFilename =
                     GeneralUtils.generateFilename(file.getOriginalFilename(), "_split.zip");
-            return WebResponseUtils.bytesToWebResponse(
-                    data, zipFilename, MediaType.APPLICATION_OCTET_STREAM);
+            return WebResponseUtils.zipFileToWebResponse(outputTempFile, zipFilename);
+        } catch (Exception e) {
+            outputTempFile.close();
+            throw e;
         }
     }
 }

app/core/src/main/java/stirling/software/SPDF/controller/api/SplitPdfByChaptersController.java

@@ -1,8 +1,6 @@
 package stirling.software.SPDF.controller.api;
 
-import java.io.ByteArrayOutputStream;
 import java.nio.file.Files;
-import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -17,6 +15,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -36,6 +35,8 @@ import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.service.PdfMetadataService;
 import stirling.software.common.util.ExceptionUtils;
 import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
 
 @GeneralApi
@@ -47,6 +48,8 @@ public class SplitPdfByChaptersController {
 
     private final CustomPDFDocumentFactory pdfDocumentFactory;
 
+    private final TempFileManager tempFileManager;
+
     private static List<Bookmark> extractOutlineItems(
             PDDocument sourceDocument,
             PDOutlineItem current,
@@ -122,22 +125,19 @@ public class SplitPdfByChaptersController {
     @Operation(
             summary = "Split PDFs by Chapters",
             description = "Splits a PDF into chapters and returns a ZIP file.")
-    public ResponseEntity<byte[]> splitPdf(@ModelAttribute SplitPdfByChaptersRequest request)
-            throws Exception {
+    public ResponseEntity<StreamingResponseBody> splitPdf(
+            @ModelAttribute SplitPdfByChaptersRequest request) throws Exception {
         MultipartFile file = request.getFileInput();
-        PDDocument sourceDocument = null;
-        Path zipFile = null;
 
-        try {
-            boolean includeMetadata = Boolean.TRUE.equals(request.getIncludeMetadata());
-            Integer bookmarkLevel =
-                    request.getBookmarkLevel(); // levels start from 0 (top most bookmarks)
-            if (bookmarkLevel < 0) {
-                throw ExceptionUtils.createIllegalArgumentException(
-                        "error.invalidArgument", "Invalid argument: {0}", "bookmark level");
-            }
-            sourceDocument = pdfDocumentFactory.load(file);
+        boolean includeMetadata = Boolean.TRUE.equals(request.getIncludeMetadata());
+        Integer bookmarkLevel =
+                request.getBookmarkLevel(); // levels start from 0 (top most bookmarks)
+        if (bookmarkLevel < 0) {
+            throw ExceptionUtils.createIllegalArgumentException(
+                    "error.invalidArgument", "Invalid argument: {0}", "bookmark level");
+        }
 
+        try (PDDocument sourceDocument = pdfDocumentFactory.load(file)) {
             PDDocumentOutline outline = sourceDocument.getDocumentCatalog().getDocumentOutline();
 
             if (outline == null) {
@@ -157,12 +157,10 @@ public class SplitPdfByChaptersController {
                                 bookmarkLevel);
                 // to handle last page edge case
                 bookmarks.get(bookmarks.size() - 1).setEndPage(sourceDocument.getNumberOfPages());
-                Bookmark lastBookmark = bookmarks.get(bookmarks.size() - 1);
 
             } catch (Exception e) {
                 ExceptionUtils.logException("outline extraction", e);
-                return ResponseEntity.internalServerError()
-                        .body("Unable to extract outline items".getBytes());
+                throw e;
             }
 
             boolean allowDuplicates = Boolean.TRUE.equals(request.getAllowDuplicates());
@@ -181,29 +179,10 @@ public class SplitPdfByChaptersController {
                         bookmark.getStartPage(),
                         bookmark.getEndPage());
             }
-            List<ByteArrayOutputStream> splitDocumentsBoas =
-                    getSplitDocumentsBoas(sourceDocument, bookmarks, includeMetadata);
-
-            zipFile = createZipFile(bookmarks, splitDocumentsBoas);
-
-            byte[] data = Files.readAllBytes(zipFile);
-            Files.deleteIfExists(zipFile);
 
+            TempFile zipTempFile = createZipFile(sourceDocument, bookmarks, includeMetadata);
             String filename = GeneralUtils.generateFilename(file.getOriginalFilename(), "");
-            sourceDocument.close();
-            return WebResponseUtils.bytesToWebResponse(
-                    data, filename + ".zip", MediaType.APPLICATION_OCTET_STREAM);
-        } finally {
-            try {
-                if (sourceDocument != null) {
-                    sourceDocument.close();
-                }
-                if (zipFile != null) {
-                    Files.deleteIfExists(zipFile);
-                }
-            } catch (Exception e) {
-                log.error("Error while cleaning up resources", e);
-            }
+            return WebResponseUtils.zipFileToWebResponse(zipTempFile, filename + ".zip");
         }
     }
 
@@ -232,72 +211,55 @@ public class SplitPdfByChaptersController {
         return bookmarks;
     }
 
-    private Path createZipFile(
-            List<Bookmark> bookmarks, List<ByteArrayOutputStream> splitDocumentsBoas)
-            throws Exception {
-        Path zipFile = Files.createTempFile("split_documents", ".zip");
-        String fileNumberFormatter = "%0" + (Integer.toString(bookmarks.size()).length()) + "d ";
-        try (ZipOutputStream zipOut = new ZipOutputStream(Files.newOutputStream(zipFile))) {
-            for (int i = 0; i < splitDocumentsBoas.size(); i++) {
-
-                // split files will be named as "[FILE_NUMBER] [BOOKMARK_TITLE].pdf"
-
-                String fileName =
-                        String.format(Locale.ROOT, fileNumberFormatter, i)
-                                + bookmarks.get(i).getTitle()
-                                + ".pdf";
-                ByteArrayOutputStream baos = splitDocumentsBoas.get(i);
-                byte[] pdf = baos.toByteArray();
-
-                ZipEntry pdfEntry = new ZipEntry(fileName);
-                zipOut.putNextEntry(pdfEntry);
-                zipOut.write(pdf);
-                zipOut.closeEntry();
-
-                log.debug("Wrote split document {} to zip file", fileName);
-            }
-        } catch (Exception e) {
-            log.error("Failed writing to zip", e);
-            throw e;
-        }
-
-        log.info("Successfully created zip file with split documents: {}", zipFile);
-        return zipFile;
-    }
-
-    public List<ByteArrayOutputStream> getSplitDocumentsBoas(
+    private TempFile createZipFile(
             PDDocument sourceDocument, List<Bookmark> bookmarks, boolean includeMetadata)
             throws Exception {
-        List<ByteArrayOutputStream> splitDocumentsBoas = new ArrayList<>();
-        PdfMetadata metadata = null;
-        if (includeMetadata) {
-            metadata = pdfMetadataService.extractMetadataFromPdf(sourceDocument);
-        }
-        for (Bookmark bookmark : bookmarks) {
-            try (PDDocument splitDocument = new PDDocument()) {
-                boolean isSinglePage = (bookmark.getStartPage() == bookmark.getEndPage());
+        PdfMetadata metadata =
+                includeMetadata ? pdfMetadataService.extractMetadataFromPdf(sourceDocument) : null;
+        String fileNumberFormatter = "%0" + (Integer.toString(bookmarks.size()).length()) + "d ";
+        TempFile zipTempFile = new TempFile(tempFileManager, ".zip");
+        try {
+            try (ZipOutputStream zipOut =
+                    new ZipOutputStream(Files.newOutputStream(zipTempFile.getPath()))) {
+                for (int i = 0; i < bookmarks.size(); i++) {
+                    Bookmark bookmark = bookmarks.get(i);
+                    try (PDDocument splitDocument = new PDDocument()) {
+                        boolean isSinglePage = (bookmark.getStartPage() == bookmark.getEndPage());
 
-                for (int i = bookmark.getStartPage();
-                        i < bookmark.getEndPage() + (isSinglePage ? 1 : 0);
-                        i++) {
-                    PDPage page = sourceDocument.getPage(i);
-                    splitDocument.addPage(page);
-                    log.debug("Adding page {} to split document", i);
+                        for (int pg = bookmark.getStartPage();
+                                pg < bookmark.getEndPage() + (isSinglePage ? 1 : 0);
+                                pg++) {
+                            PDPage page = sourceDocument.getPage(pg);
+                            splitDocument.addPage(page);
+                            log.debug("Adding page {} to split document", pg);
+                        }
+                        if (includeMetadata) {
+                            pdfMetadataService.setMetadataToPdf(splitDocument, metadata);
+                        }
+
+                        // split files will be named as "[FILE_NUMBER] [BOOKMARK_TITLE].pdf"
+                        String fileName =
+                                String.format(Locale.ROOT, fileNumberFormatter, i)
+                                        + bookmark.getTitle()
+                                        + ".pdf";
+                        zipOut.putNextEntry(new ZipEntry(fileName));
+                        splitDocument.save(zipOut);
+                        zipOut.closeEntry();
+                        log.debug("Wrote split document {} to zip file", fileName);
+                    } catch (Exception e) {
+                        ExceptionUtils.logException("document splitting and saving", e);
+                        throw e;
+                    }
                 }
-                ByteArrayOutputStream baos = new ByteArrayOutputStream();
-                if (includeMetadata) {
-                    pdfMetadataService.setMetadataToPdf(splitDocument, metadata);
-                }
-
-                splitDocument.save(baos);
-
-                splitDocumentsBoas.add(baos);
-            } catch (Exception e) {
-                ExceptionUtils.logException("document splitting and saving", e);
-                throw e;
             }
+            log.info(
+                    "Successfully created zip file with split documents: {}",
+                    zipTempFile.getPath());
+            return zipTempFile;
+        } catch (Exception e) {
+            zipTempFile.close();
+            throw e;
         }
-        return splitDocumentsBoas;
     }
 }
 

app/core/src/main/java/stirling/software/SPDF/controller/api/SplitPdfBySizeController.java

@@ -3,7 +3,6 @@ package stirling.software.SPDF.controller.api;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.Path;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -13,9 +12,11 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
+import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
@@ -50,8 +51,8 @@ public class SplitPdfBySizeController {
                             + " if 10MB and each page is 1MB and you enter 2MB then 5 docs each 2MB"
                             + " (rounded so that it accepts 1.9MB but not 2.1MB) Input:PDF"
                             + " Output:ZIP-PDF Type:SISO")
-    public ResponseEntity<byte[]> autoSplitPdf(@ModelAttribute SplitPdfBySizeOrCountRequest request)
-            throws Exception {
+    public ResponseEntity<StreamingResponseBody> autoSplitPdf(
+            @ModelAttribute SplitPdfBySizeOrCountRequest request) throws Exception {
 
         log.debug("Starting PDF split process with request: {}", request);
         MultipartFile file = request.getFileInput();
@@ -59,63 +60,51 @@ public class SplitPdfBySizeController {
         String filename = GeneralUtils.generateFilename(file.getOriginalFilename(), "");
         log.debug("Base filename for output: {}", filename);
 
-        try (TempFile zipTempFile = new TempFile(tempFileManager, ".zip")) {
-            Path managedZipPath = zipTempFile.getPath();
-            log.debug("Created temporary managed zip file: {}", managedZipPath);
-            try {
-                log.debug("Reading input file bytes");
-                byte[] pdfBytes = file.getBytes();
-                log.debug("Successfully read {} bytes from input file", pdfBytes.length);
+        TempFile zipTempFile = new TempFile(tempFileManager, ".zip");
+        try {
+            log.debug("Created temporary managed zip file: {}", zipTempFile.getPath());
+            log.debug("Creating ZIP output stream");
+            try (ZipOutputStream zipOut =
+                            new ZipOutputStream(Files.newOutputStream(zipTempFile.getPath()));
+                    PDDocument sourceDocument = pdfDocumentFactory.load(file)) {
+                log.debug(
+                        "Successfully loaded PDF with {} pages", sourceDocument.getNumberOfPages());
 
-                log.debug("Creating ZIP output stream");
-                try (ZipOutputStream zipOut =
-                        new ZipOutputStream(Files.newOutputStream(managedZipPath))) {
-                    log.debug("Loading PDF document");
-                    try (PDDocument sourceDocument = pdfDocumentFactory.load(pdfBytes)) {
-                        log.debug(
-                                "Successfully loaded PDF with {} pages",
-                                sourceDocument.getNumberOfPages());
+                int type = request.getSplitType();
+                String value = request.getSplitValue();
+                log.debug("Split type: {}, Split value: {}", type, value);
 
-                        int type = request.getSplitType();
-                        String value = request.getSplitValue();
-                        log.debug("Split type: {}, Split value: {}", type, value);
-
-                        if (type == 0) {
-                            log.debug("Processing split by size");
-                            long maxBytes = GeneralUtils.convertSizeToBytes(value);
-                            log.debug("Max bytes per document: {}", maxBytes);
-                            handleSplitBySize(sourceDocument, maxBytes, zipOut, filename);
-                        } else if (type == 1) {
-                            log.debug("Processing split by page count");
-                            int pageCount = Integer.parseInt(value);
-                            log.debug("Pages per document: {}", pageCount);
-                            handleSplitByPageCount(sourceDocument, pageCount, zipOut, filename);
-                        } else if (type == 2) {
-                            log.debug("Processing split by document count");
-                            int documentCount = Integer.parseInt(value);
-                            log.debug("Total number of documents: {}", documentCount);
-                            handleSplitByDocCount(sourceDocument, documentCount, zipOut, filename);
-                        } else {
-                            log.error("Invalid split type: {}", type);
-                            throw ExceptionUtils.createIllegalArgumentException(
-                                    "error.invalidArgument",
-                                    "Invalid argument: {0}",
-                                    "split type: " + type);
-                        }
-                        log.debug("PDF splitting completed successfully");
-                    }
+                if (type == 0) {
+                    log.debug("Processing split by size");
+                    long maxBytes = GeneralUtils.convertSizeToBytes(value);
+                    log.debug("Max bytes per document: {}", maxBytes);
+                    handleSplitBySize(sourceDocument, maxBytes, zipOut, filename);
+                } else if (type == 1) {
+                    log.debug("Processing split by page count");
+                    int pageCount = Integer.parseInt(value);
+                    log.debug("Pages per document: {}", pageCount);
+                    handleSplitByPageCount(sourceDocument, pageCount, zipOut, filename);
+                } else if (type == 2) {
+                    log.debug("Processing split by document count");
+                    int documentCount = Integer.parseInt(value);
+                    log.debug("Total number of documents: {}", documentCount);
+                    handleSplitByDocCount(sourceDocument, documentCount, zipOut, filename);
+                } else {
+                    log.error("Invalid split type: {}", type);
+                    throw ExceptionUtils.createIllegalArgumentException(
+                            "error.invalidArgument",
+                            "Invalid argument: {0}",
+                            "split type: " + type);
                 }
-
-                byte[] data = Files.readAllBytes(managedZipPath);
-                log.debug("Successfully read {} bytes from ZIP file", data.length);
-
-                log.debug("Returning response with {} bytes of data", data.length);
-                return WebResponseUtils.bytesToWebResponse(
-                        data, filename + ".zip", MediaType.APPLICATION_OCTET_STREAM);
-            } catch (Exception e) {
-                ExceptionUtils.logException("PDF splitting process", e);
-                throw e; // Re-throw to ensure proper error response
+                log.debug("PDF splitting completed successfully");
             }
+
+            log.debug("Returning streaming response for zip file");
+            return WebResponseUtils.zipFileToWebResponse(zipTempFile, filename + ".zip");
+        } catch (Exception e) {
+            ExceptionUtils.logException("PDF splitting process", e);
+            zipTempFile.close();
+            throw e;
         }
     }
 
@@ -124,6 +113,7 @@ public class SplitPdfBySizeController {
             throws IOException {
         log.debug("Starting handleSplitBySize with maxBytes={}", maxBytes);
 
+        @Getter
         class DocHolder implements AutoCloseable {
             private PDDocument doc;
 
@@ -131,10 +121,6 @@ public class SplitPdfBySizeController {
                 this.doc = doc;
             }
 
-            public PDDocument getDoc() {
-                return doc;
-            }
-
             public void setDoc(PDDocument doc) {
                 if (this.doc != null) {
                     try {

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java

@@ -22,6 +22,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -51,6 +52,7 @@ import stirling.software.common.util.PdfUtils;
 import stirling.software.common.util.ProcessExecutor;
 import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
 import stirling.software.common.util.RegexPatternUtils;
+import stirling.software.common.util.TempFile;
 import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
 
@@ -78,7 +80,7 @@ public class ConvertImgPDFController {
                     "This endpoint converts a PDF file to image(s) with the specified image format,"
                             + " color type, and DPI. Users can choose to get a single image or multiple"
                             + " images.  Input:PDF Output:Image Type:SI-Conditional")
-    public ResponseEntity<byte[]> convertToImage(@ModelAttribute ConvertToImageRequest request)
+    public ResponseEntity<?> convertToImage(@ModelAttribute ConvertToImageRequest request)
             throws Exception {
         MultipartFile file = request.getFileInput();
         String imageFormat = request.getImageFormat();
@@ -180,28 +182,33 @@ public class ConvertImgPDFController {
                             "No WebP files were created. " + resultProcess.getMessages());
                 }
 
-                byte[] bodyBytes = new byte[0];
-
                 if (webpFiles.size() == 1) {
-                    // Return the single WebP file directly
                     Path webpFilePath = webpFiles.get(0);
-                    bodyBytes = Files.readAllBytes(webpFilePath);
+                    byte[] webpBytes = Files.readAllBytes(webpFilePath);
+                    Files.deleteIfExists(tempFile);
+                    tempFile = null;
+                    FileUtils.deleteDirectory(tempOutputDir.toFile());
+                    tempOutputDir = null;
+                    String docName = filename + "." + imageFormat;
+                    MediaType mediaType = MediaType.parseMediaType(getMediaType(imageFormat));
+                    return WebResponseUtils.bytesToWebResponse(webpBytes, docName, mediaType);
                 } else {
-                    // Create a ZIP file containing all WebP images
-                    try (ByteArrayOutputStream zipOutputStream = new ByteArrayOutputStream();
-                            ZipOutputStream zos = new ZipOutputStream(zipOutputStream)) {
+                    ByteArrayOutputStream zipBAOS = new ByteArrayOutputStream();
+                    try (ZipOutputStream zos = new ZipOutputStream(zipBAOS)) {
                         for (Path webpFile : webpFiles) {
                             zos.putNextEntry(new ZipEntry(webpFile.getFileName().toString()));
                             Files.copy(webpFile, zos);
                             zos.closeEntry();
                         }
-                        bodyBytes = zipOutputStream.toByteArray();
                     }
+                    Files.deleteIfExists(tempFile);
+                    tempFile = null;
+                    FileUtils.deleteDirectory(tempOutputDir.toFile());
+                    tempOutputDir = null;
+                    String zipFilename = filename + "_convertedToImages.zip";
+                    return WebResponseUtils.bytesToWebResponse(
+                            zipBAOS.toByteArray(), zipFilename, MediaType.APPLICATION_OCTET_STREAM);
                 }
-                // Clean up the temporary files
-                Files.deleteIfExists(tempFile);
-                if (tempOutputDir != null) FileUtils.deleteDirectory(tempOutputDir.toFile());
-                result = bodyBytes;
             }
 
             if (singleImage) {
@@ -267,8 +274,8 @@ public class ConvertImgPDFController {
             description =
                     "This endpoint converts a CBZ (ZIP) comic book archive to a PDF file. "
                             + "Input:CBZ Output:PDF Type:SISO")
-    public ResponseEntity<?> convertCbzToPdf(@ModelAttribute ConvertCbzToPdfRequest request)
-            throws IOException {
+    public ResponseEntity<StreamingResponseBody> convertCbzToPdf(
+            @ModelAttribute ConvertCbzToPdfRequest request) throws IOException {
         MultipartFile file = request.getFileInput();
         boolean optimizeForEbook = request.isOptimizeForEbook();
 
@@ -278,13 +285,13 @@ public class ConvertImgPDFController {
             optimizeForEbook = false;
         }
 
-        byte[] pdfBytes =
+        TempFile pdfFile =
                 CbzUtils.convertCbzToPdf(
                         file, pdfDocumentFactory, tempFileManager, optimizeForEbook);
 
         String filename = createConvertedFilename(file.getOriginalFilename(), "_converted.pdf");
 
-        return WebResponseUtils.bytesToWebResponse(pdfBytes, filename);
+        return WebResponseUtils.pdfFileToWebResponse(pdfFile, filename);
     }
 
     @AutoJobPostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/pdf/cbz")
@@ -293,8 +300,8 @@ public class ConvertImgPDFController {
             description =
                     "This endpoint converts a PDF file to a CBZ (ZIP) comic book archive. "
                             + "Input:PDF Output:CBZ Type:SISO")
-    public ResponseEntity<?> convertPdfToCbz(@ModelAttribute ConvertPdfToCbzRequest request)
-            throws IOException {
+    public ResponseEntity<StreamingResponseBody> convertPdfToCbz(
+            @ModelAttribute ConvertPdfToCbzRequest request) throws IOException {
         MultipartFile file = request.getFileInput();
         int dpi = request.getDpi();
 
@@ -302,12 +309,12 @@ public class ConvertImgPDFController {
             dpi = 300;
         }
 
-        byte[] cbzBytes = PdfToCbzUtils.convertPdfToCbz(file, dpi, pdfDocumentFactory);
+        TempFile cbzFile =
+                PdfToCbzUtils.convertPdfToCbz(file, dpi, pdfDocumentFactory, tempFileManager);
 
         String filename = createConvertedFilename(file.getOriginalFilename(), "_converted.cbz");
 
-        return WebResponseUtils.bytesToWebResponse(
-                cbzBytes, filename, MediaType.APPLICATION_OCTET_STREAM);
+        return WebResponseUtils.zipFileToWebResponse(cbzFile, filename);
     }
 
     @AutoJobPostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/cbr/pdf")

app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertPdfJsonController.java

@@ -39,6 +39,8 @@ import stirling.software.common.util.WebResponseUtils;
 public class ConvertPdfJsonController {
 
     private static final Pattern FILE_EXTENSION_PATTERN = Pattern.compile("[.][^.]+$");
+    private static final Pattern WHITESPACE_PATTERN = Pattern.compile("[\\r\\n\\t]+");
+    private static final Pattern NON_PRINTABLE_PATTERN = Pattern.compile("[^\\x20-\\x7E]");
     private final PdfJsonConversionService pdfJsonConversionService;
 
     @Autowired(required = false)
@@ -259,7 +261,10 @@ public class ConvertPdfJsonController {
             if (length > 0) {
                 int start = Math.max(0, length - 64);
                 tail = new String(jsonBytes, start, length - start, StandardCharsets.UTF_8);
-                tail = tail.replaceAll("[\\r\\n\\t]+", " ").replaceAll("[^\\x20-\\x7E]", "?");
+                tail =
+                        NON_PRINTABLE_PATTERN
+                                .matcher(WHITESPACE_PATTERN.matcher(tail).replaceAll(" "))
+                                .replaceAll("?");
             }
             log.debug(
                     "Returning {} JSON response ({} bytes, endsWithJson={}, tail='{}')",
@@ -421,9 +426,9 @@ public class ConvertPdfJsonController {
     private String truncateForLog(String value) {
         int max = 64;
         if (value.length() <= max) {
-            return value.replaceAll("[\\r\\n\\t]+", " ");
+            return WHITESPACE_PATTERN.matcher(value).replaceAll(" ");
         }
-        return value.substring(0, max).replaceAll("[\\r\\n\\t]+", " ") + "...";
+        return WHITESPACE_PATTERN.matcher(value.substring(0, max)).replaceAll(" ") + "...";
     }
 
     /**

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java

@@ -67,7 +67,7 @@ public class ExtractImageScansController {
         MultipartFile inputFile = request.getFileInput();
 
         String fileName = inputFile.getOriginalFilename();
-        String extension = fileName.substring(fileName.lastIndexOf(".") + 1);
+        String extension = fileName.substring(fileName.lastIndexOf('.') + 1);
 
         List<String> images = new ArrayList<>();
 

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImagesController.java

@@ -5,6 +5,7 @@ import java.awt.image.BufferedImage;
 import java.awt.image.RenderedImage;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
@@ -28,6 +29,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -42,6 +44,8 @@ import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.util.ExceptionUtils;
 import stirling.software.common.util.GeneralUtils;
 import stirling.software.common.util.ImageProcessingUtils;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
 
 @MiscApi
@@ -50,6 +54,7 @@ import stirling.software.common.util.WebResponseUtils;
 public class ExtractImagesController {
 
     private final CustomPDFDocumentFactory pdfDocumentFactory;
+    private final TempFileManager tempFileManager;
 
     @AutoJobPostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/extract-images")
     @MultiFileResponse
@@ -59,111 +64,115 @@ public class ExtractImagesController {
                     "This endpoint extracts images from a given PDF file and returns them in a zip"
                             + " file. Users can specify the output image format. Input:PDF"
                             + " Output:IMAGE/ZIP Type:SIMO")
-    public ResponseEntity<byte[]> extractImages(@ModelAttribute PDFExtractImagesRequest request)
+    public ResponseEntity<StreamingResponseBody> extractImages(
+            @ModelAttribute PDFExtractImagesRequest request)
             throws IOException, InterruptedException, ExecutionException {
         MultipartFile file = request.getFileInput();
         String format = request.getFormat();
         boolean allowDuplicates = Boolean.TRUE.equals(request.getAllowDuplicates());
-        PDDocument document = pdfDocumentFactory.load(file);
-
-        // Determine if multithreading should be used based on PDF size or number of pages
-        boolean useMultithreading = shouldUseMultithreading(file, document);
-
-        // Create ByteArrayOutputStream to write zip file to byte array
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-
-        // Create ZipOutputStream to create zip file
-        ZipOutputStream zos = new ZipOutputStream(baos);
-
-        // Set compression level
-        zos.setLevel(Deflater.BEST_COMPRESSION);
 
         String filename = GeneralUtils.removeExtension(file.getOriginalFilename());
         Set<byte[]> processedImages = new HashSet<>();
 
-        if (useMultithreading) {
-            // Virtual thread executor — lightweight threads ideal for I/O-bound image extraction
-            ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
-            Set<Future<Void>> futures = new HashSet<>();
+        TempFile zipTempFile = new TempFile(tempFileManager, ".zip");
+        try (ZipOutputStream zos =
+                        new ZipOutputStream(Files.newOutputStream(zipTempFile.getPath()));
+                PDDocument document = pdfDocumentFactory.load(file)) {
 
-            // Safely iterate over each page, handling corrupt PDFs where page count might be wrong
-            try {
-                int pageCount = document.getPages().getCount();
-                log.debug("Document reports {} pages", pageCount);
+            // Set compression level
+            zos.setLevel(Deflater.BEST_COMPRESSION);
 
-                int consecutiveFailures = 0;
+            // Determine if multithreading should be used based on PDF size or number of pages
+            boolean useMultithreading = shouldUseMultithreading(file, document);
 
-                for (int pgNum = 0; pgNum < pageCount; pgNum++) {
-                    try {
-                        PDPage page = document.getPage(pgNum);
-                        consecutiveFailures = 0; // Reset on success
-                        final int currentPageNum = pgNum + 1; // Convert to 1-based page numbering
-                        Future<Void> future =
-                                executor.submit(
-                                        () -> {
-                                            try {
-                                                // Call the image extraction method for each page
-                                                extractImagesFromPage(
-                                                        page,
-                                                        format,
-                                                        filename,
-                                                        currentPageNum,
-                                                        processedImages,
-                                                        zos,
-                                                        allowDuplicates);
-                                            } catch (Exception e) {
-                                                // Log the error and continue processing other pages
-                                                ExceptionUtils.logException(
-                                                        "image extraction from page "
-                                                                + currentPageNum,
-                                                        e);
-                                            }
+            if (useMultithreading) {
+                ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
+                Set<Future<Void>> futures = new HashSet<>();
 
-                                            return null; // Callable requires a return type
-                                        });
+                try {
+                    int pageCount = document.getPages().getCount();
+                    log.debug("Document reports {} pages", pageCount);
 
-                        // Add the Future object to the list to track completion
-                        futures.add(future);
-                    } catch (Exception e) {
-                        consecutiveFailures++;
-                        ExceptionUtils.logException("page access for page " + (pgNum + 1), e);
+                    int consecutiveFailures = 0;
 
-                        if (consecutiveFailures >= 3) {
-                            log.warn("Stopping page iteration after 3 consecutive failures");
-                            break;
+                    for (int pgNum = 0; pgNum < pageCount; pgNum++) {
+                        try {
+                            PDPage page = document.getPage(pgNum);
+                            consecutiveFailures = 0; // Reset on success
+                            final int currentPageNum =
+                                    pgNum + 1; // Convert to 1-based page numbering
+                            Future<Void> future =
+                                    executor.submit(
+                                            () -> {
+                                                try {
+                                                    // Call the image extraction method for each
+                                                    // page
+                                                    extractImagesFromPage(
+                                                            page,
+                                                            format,
+                                                            filename,
+                                                            currentPageNum,
+                                                            processedImages,
+                                                            zos,
+                                                            allowDuplicates);
+                                                } catch (Exception e) {
+                                                    // Log the error and continue processing other
+                                                    // pages
+                                                    ExceptionUtils.logException(
+                                                            "image extraction from page "
+                                                                    + currentPageNum,
+                                                            e);
+                                                }
+
+                                                return null; // Callable requires a return type
+                                            });
+
+                            // Add the Future object to the list to track completion
+                            futures.add(future);
+                        } catch (Exception e) {
+                            consecutiveFailures++;
+                            ExceptionUtils.logException("page access for page " + (pgNum + 1), e);
+
+                            if (consecutiveFailures >= 3) {
+                                log.warn("Stopping page iteration after 3 consecutive failures");
+                                break;
+                            }
                         }
                     }
+                } catch (Exception e) {
+                    ExceptionUtils.logException("page count determination", e);
+                    throw e;
                 }
-            } catch (Exception e) {
-                ExceptionUtils.logException("page count determination", e);
-                throw e;
-            }
 
-            // Wait for all tasks to complete
-            for (Future<Void> future : futures) {
-                future.get();
-            }
+                // Wait for all tasks to complete
+                for (Future<Void> future : futures) {
+                    future.get();
+                }
 
-            // Close executor service
-            executor.shutdown();
-        } else {
-            // Single-threaded extraction
-            for (int pgNum = 0; pgNum < document.getPages().getCount(); pgNum++) {
-                PDPage page = document.getPage(pgNum);
-                extractImagesFromPage(
-                        page, format, filename, pgNum + 1, processedImages, zos, allowDuplicates);
+                // Close executor service
+                executor.shutdown();
+            } else {
+                // Single-threaded extraction
+                for (int pgNum = 0; pgNum < document.getPages().getCount(); pgNum++) {
+                    PDPage page = document.getPage(pgNum);
+                    extractImagesFromPage(
+                            page,
+                            format,
+                            filename,
+                            pgNum + 1,
+                            processedImages,
+                            zos,
+                            allowDuplicates);
+                }
             }
+            // document and zos closed by try-with-resources
+        } catch (Exception e) {
+            zipTempFile.close();
+            throw e;
         }
 
-        // Close PDDocument and ZipOutputStream
-        document.close();
-        zos.close();
-
-        // Create ByteArrayResource from byte array
-        byte[] zipContents = baos.toByteArray();
-
-        return WebResponseUtils.baosToWebResponse(
-                baos, filename + "_extracted-images.zip", MediaType.APPLICATION_OCTET_STREAM);
+        return WebResponseUtils.zipFileToWebResponse(
+                zipTempFile, filename + "_extracted-images.zip");
     }
 
     private boolean shouldUseMultithreading(MultipartFile file, PDDocument document) {
@@ -214,13 +223,17 @@ public class ExtractImagesController {
                     // Convert to standard RGB colorspace if needed
                     BufferedImage bufferedImage = convertToRGB(renderedImage, format);
 
-                    // Write image to zip file
+                    // Encode image outside the lock to allow parallel encoding across threads
                     String imageName = filename + "_page_" + pageNum + "_" + count++ + "." + format;
+                    ByteArrayOutputStream imageBaos = new ByteArrayOutputStream();
+                    ImageIO.write(bufferedImage, format, imageBaos);
+                    byte[] imageData = imageBaos.toByteArray();
+
+                    // Write encoded bytes to zip under lock (ZipOutputStream requires
+                    // serialization)
                     synchronized (zos) {
                         zos.putNextEntry(new ZipEntry(imageName));
-                        ByteArrayOutputStream imageBaos = new ByteArrayOutputStream();
-                        ImageIO.write(bufferedImage, format, imageBaos);
-                        zos.write(imageBaos.toByteArray());
+                        zos.write(imageData);
                         zos.closeEntry();
                     }
                 }

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/OCRController.java

@@ -94,7 +94,7 @@ public class OCRController {
             throws IOException, InterruptedException {
         MultipartFile inputFile = request.getFileInput();
         List<String> selectedLanguages = request.getLanguages();
-        Boolean sidecar = request.isSidecar();
+        boolean sidecar = request.isSidecar();
         Boolean deskew = request.isDeskew();
         Boolean clean = request.isClean();
         Boolean cleanFinal = request.isCleanFinal();

app/core/src/main/java/stirling/software/SPDF/controller/api/misc/StampController.java

@@ -233,7 +233,7 @@ public class StampController {
                 };
 
         ClassPathResource classPathResource = new ClassPathResource(resourceDir);
-        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
+        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf('.'));
 
         // Use TempFile with try-with-resources for automatic cleanup
         try (TempFile tempFileWrapper = new TempFile(tempFileManager, fileExtension)) {

app/core/src/main/java/stirling/software/SPDF/controller/api/pipeline/PipelineController.java

@@ -1,7 +1,7 @@
 package stirling.software.SPDF.controller.api.pipeline;
 
-import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
+import java.nio.file.Files;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -13,6 +13,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import io.swagger.v3.oas.annotations.Operation;
 
@@ -28,6 +29,8 @@ import stirling.software.common.annotations.AutoJobPostMapping;
 import stirling.software.common.annotations.api.PipelineApi;
 import stirling.software.common.service.PostHogService;
 import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.TempFile;
+import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
 
 import tools.jackson.core.JacksonException;
@@ -45,6 +48,8 @@ public class PipelineController {
 
     private final PostHogService postHogService;
 
+    private final TempFileManager tempFileManager;
+
     @AutoJobPostMapping(value = "/handleData", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     @MultiFileResponse
     @Operation(
@@ -53,8 +58,8 @@ public class PipelineController {
                     "This endpoint processes multiple PDF files through a configurable pipeline of operations. "
                             + "Users provide files and a JSON configuration defining the sequence of operations to perform. "
                             + "Input:PDF Output:PDF/ZIP Type:MIMO")
-    public ResponseEntity<byte[]> handleData(@ModelAttribute HandleDataRequest request)
-            throws DatabindException, JacksonException {
+    public ResponseEntity<StreamingResponseBody> handleData(
+            @ModelAttribute HandleDataRequest request) throws DatabindException, JacksonException {
         MultipartFile[] files = request.getFileInput();
         String jsonString = request.getJson();
         if (files == null) {
@@ -80,51 +85,56 @@ public class PipelineController {
             PipelineResult result = processor.runPipelineAgainstFiles(inputFiles, config);
             List<Resource> outputFiles = result.getOutputFiles();
             if (outputFiles != null && outputFiles.size() == 1) {
-                // If there is only one file, return it directly
+                // If there is only one file, return it directly — stream without int-overflow
                 Resource singleFile = outputFiles.get(0);
-                InputStream is = singleFile.getInputStream();
-                byte[] bytes = new byte[(int) singleFile.contentLength()];
-                is.read(bytes);
-                is.close();
-                log.info("Returning single file response...");
-                return WebResponseUtils.bytesToWebResponse(
-                        bytes, singleFile.getFilename(), MediaType.APPLICATION_OCTET_STREAM);
+                TempFile singleTempFile = new TempFile(tempFileManager, ".out");
+                try {
+                    try (InputStream is = singleFile.getInputStream()) {
+                        is.transferTo(Files.newOutputStream(singleTempFile.getPath()));
+                    }
+                    log.info("Returning single file response...");
+                    return WebResponseUtils.fileToWebResponse(
+                            singleTempFile,
+                            singleFile.getFilename(),
+                            MediaType.APPLICATION_OCTET_STREAM);
+                } catch (Exception e) {
+                    singleTempFile.close();
+                    throw e;
+                }
             } else if (outputFiles == null) {
                 return null;
             }
-            // Create a ByteArrayOutputStream to hold the zip
-            ByteArrayOutputStream baos = new ByteArrayOutputStream();
-            ZipOutputStream zipOut = new ZipOutputStream(baos);
-            // A map to keep track of filenames and their counts
-            Map<String, Integer> filenameCount = new HashMap<>();
-            // Loop through each file and add it to the zip
-            for (Resource file : outputFiles) {
-                String originalFilename = file.getFilename();
-                String filename = originalFilename;
-                // Check if the filename already exists, and modify it if necessary
-                if (filenameCount.containsKey(originalFilename)) {
-                    int count = filenameCount.get(originalFilename);
-                    assert originalFilename != null;
-                    filename = GeneralUtils.generateFilename(originalFilename, "(" + count + ")");
-                    filenameCount.put(originalFilename, count + 1);
-                } else {
-                    filenameCount.put(originalFilename, 1);
+            // Multiple files: stream into a zip TempFile
+            TempFile zipTempFile = new TempFile(tempFileManager, ".zip");
+            try {
+                Map<String, Integer> filenameCount = new HashMap<>();
+                try (ZipOutputStream zipOut =
+                        new ZipOutputStream(Files.newOutputStream(zipTempFile.getPath()))) {
+                    for (Resource file : outputFiles) {
+                        String originalFilename = file.getFilename();
+                        String filename = originalFilename;
+                        if (filenameCount.containsKey(originalFilename)) {
+                            int count = filenameCount.get(originalFilename);
+                            filename =
+                                    GeneralUtils.generateFilename(
+                                            originalFilename, "(" + count + ")");
+                            filenameCount.put(originalFilename, count + 1);
+                        } else {
+                            filenameCount.put(originalFilename, 1);
+                        }
+                        zipOut.putNextEntry(new ZipEntry(filename));
+                        try (InputStream is = file.getInputStream()) {
+                            is.transferTo(zipOut);
+                        }
+                        zipOut.closeEntry();
+                    }
                 }
-                ZipEntry zipEntry = new ZipEntry(filename);
-                zipOut.putNextEntry(zipEntry);
-                // Read the file into a byte array
-                InputStream is = file.getInputStream();
-                byte[] bytes = new byte[(int) file.contentLength()];
-                is.read(bytes);
-                // Write the bytes of the file to the zip
-                zipOut.write(bytes, 0, bytes.length);
-                zipOut.closeEntry();
-                is.close();
+                log.info("Returning zipped file response...");
+                return WebResponseUtils.zipFileToWebResponse(zipTempFile, "output.zip");
+            } catch (Exception e) {
+                zipTempFile.close();
+                throw e;
             }
-            zipOut.close();
-            log.info("Returning zipped file response...");
-            return WebResponseUtils.baosToWebResponse(
-                    baos, "output.zip", MediaType.APPLICATION_OCTET_STREAM);
         } catch (Exception e) {
             log.error("Error handling data: ", e);
             return null;

app/core/src/main/java/stirling/software/SPDF/controller/api/pipeline/PipelineDirectoryProcessor.java

@@ -254,7 +254,7 @@ public class PipelineDirectoryProcessor {
                                         String extension =
                                                 filename.contains(".")
                                                         ? filename.substring(
-                                                                        filename.lastIndexOf(".")
+                                                                        filename.lastIndexOf('.')
                                                                                 + 1)
                                                                 .toLowerCase(Locale.ROOT)
                                                         : "";

app/core/src/main/java/stirling/software/SPDF/controller/api/pipeline/PipelineProcessor.java

@@ -67,7 +67,7 @@ public class PipelineProcessor {
 
     public static String removeTrailingNaming(String filename) {
         // Splitting filename into name and extension
-        int dotIndex = filename.lastIndexOf(".");
+        int dotIndex = filename.lastIndexOf('.');
         if (dotIndex == -1) {
             // No extension found
             return filename;
@@ -75,7 +75,7 @@ public class PipelineProcessor {
         String name = filename.substring(0, dotIndex);
         String extension = filename.substring(dotIndex);
         // Finding the last underscore
-        int underscoreIndex = name.lastIndexOf("_");
+        int underscoreIndex = name.lastIndexOf('_');
         if (underscoreIndex == -1) {
             // No underscore found
             return filename;
@@ -173,7 +173,7 @@ public class PipelineProcessor {
                         String providedExtension = "no extension";
                         if (filename != null && filename.contains(".")) {
                             providedExtension =
-                                    filename.substring(filename.lastIndexOf("."))
+                                    filename.substring(filename.lastIndexOf('.'))
                                             .toLowerCase(Locale.ROOT);
                         }
 
@@ -248,7 +248,7 @@ public class PipelineProcessor {
                                                 String filename = file.getFilename();
                                                 if (filename != null && filename.contains(".")) {
                                                     return filename.substring(
-                                                                    filename.lastIndexOf("."))
+                                                                    filename.lastIndexOf('.'))
                                                             .toLowerCase(Locale.ROOT);
                                                 }
                                                 return "no extension";
@@ -450,7 +450,21 @@ public class PipelineProcessor {
         return isZip(data, null);
     }
 
+    private static final int MAX_UNZIP_DEPTH = 10;
+
     private List<Resource> unzip(Resource data, PipelineResult result) throws IOException {
+        return unzip(data, result, 0);
+    }
+
+    private List<Resource> unzip(Resource data, PipelineResult result, int depth)
+            throws IOException {
+        if (depth > MAX_UNZIP_DEPTH) {
+            log.warn(
+                    "ZIP nesting depth {} exceeds limit {}, treating as file",
+                    depth,
+                    MAX_UNZIP_DEPTH);
+            return List.of(data);
+        }
         log.info("Unzipping data of length: {}", data.contentLength());
         List<Resource> unzippedFiles = new ArrayList<>();
         try (InputStream bais = data.getInputStream();
@@ -481,7 +495,7 @@ public class PipelineProcessor {
                 // If the unzipped file is a zip file, unzip it
                 if (isZip(fileResource, filename)) {
                     log.info("File {} is a zip file. Unzipping...", filename);
-                    unzippedFiles.addAll(unzip(fileResource, result));
+                    unzippedFiles.addAll(unzip(fileResource, result, depth + 1));
                 } else {
                     unzippedFiles.add(fileResource);
                 }

app/core/src/main/java/stirling/software/SPDF/controller/api/security/WatermarkController.java

@@ -188,7 +188,7 @@ public class WatermarkController {
                 };
 
         ClassPathResource classPathResource = new ClassPathResource(resourceDir);
-        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf("."));
+        String fileExtension = resourceDir.substring(resourceDir.lastIndexOf('.'));
         File tempFile = Files.createTempFile("NotoSansFont", fileExtension).toFile();
         try (InputStream is = classPathResource.getInputStream();
                 FileOutputStream os = new FileOutputStream(tempFile)) {

app/core/src/main/java/stirling/software/SPDF/exception/GlobalExceptionHandler.java

@@ -3,6 +3,7 @@ package stirling.software.SPDF.exception;
 import java.io.IOException;
 import java.net.URI;
 import java.time.Instant;
+import java.util.LinkedHashMap;
 import java.util.List;
 
 import org.springframework.context.MessageSource;
@@ -23,8 +24,6 @@ import org.springframework.web.multipart.MaxUploadSizeExceededException;
 import org.springframework.web.multipart.support.MissingServletRequestPartException;
 import org.springframework.web.servlet.NoHandlerFoundException;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 
@@ -35,6 +34,8 @@ import stirling.software.common.util.ExceptionUtils;
 import stirling.software.common.util.ExceptionUtils.*;
 import stirling.software.common.util.RegexPatternUtils;
 
+import tools.jackson.databind.ObjectMapper;
+
 /**
  * Returns RFC 7807 Problem Details for HTTP APIs, ensuring consistent error responses across the
  * application.
@@ -870,7 +871,7 @@ public class GlobalExceptionHandler {
 
         // Use ObjectMapper to properly escape JSON values and prevent XSS
         ObjectMapper mapper = new ObjectMapper();
-        java.util.Map<String, Object> errorMap = new java.util.LinkedHashMap<>();
+        java.util.Map<String, Object> errorMap = new LinkedHashMap<>();
         errorMap.put("type", "about:blank");
         errorMap.put("title", "Not Acceptable");
         errorMap.put("status", 406);

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonAnnotation.java

@@ -1,7 +1,5 @@
 package stirling.software.SPDF.model.json;
 
-import java.util.List;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import lombok.AllArgsConstructor;
@@ -27,13 +25,13 @@ public class PdfJsonAnnotation {
     private String contents;
 
     /** Annotation rectangle [x1, y1, x2, y2] */
-    private List<Float> rect;
+    private float[] rect;
 
     /** Annotation appearance characteristics */
     private String appearanceState;
 
     /** Color components (e.g., [r, g, b] for RGB) */
-    private List<Float> color;
+    private float[] color;
 
     /** Annotation flags (print, hidden, etc.) */
     private Integer flags;

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonDocument.java

@@ -14,7 +14,7 @@ import lombok.NoArgsConstructor;
 @Builder
 @NoArgsConstructor
 @AllArgsConstructor
-@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonInclude(JsonInclude.Include.NON_DEFAULT)
 public class PdfJsonDocument {
 
     private PdfJsonMetadata metadata;
@@ -23,7 +23,7 @@ public class PdfJsonDocument {
     private String xmpMetadata;
 
     /** Indicates that images should be loaded lazily via API rather than embedded in the JSON. */
-    private Boolean lazyImages;
+    private boolean lazyImages;
 
     @Builder.Default private List<PdfJsonFont> fonts = new ArrayList<>();
 

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonFontConversionCandidate.java

@@ -1,7 +1,5 @@
 package stirling.software.SPDF.model.json;
 
-import java.util.List;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import lombok.AllArgsConstructor;
@@ -65,5 +63,5 @@ public class PdfJsonFontConversionCandidate {
     private String diagnostics;
 
     /** Known unicode/codepoint coverage derived from the conversion strategy. */
-    private List<Integer> glyphCoverage;
+    private int[] glyphCoverage;
 }

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonFormField.java

@@ -45,13 +45,13 @@ public class PdfJsonFormField {
     private Integer pageNumber;
 
     /** Field rectangle [x1, y1, x2, y2] on the page */
-    private List<Float> rect;
+    private float[] rect;
 
     /** For choice fields: list of options */
     private List<String> options;
 
     /** For choice fields: selected indices */
-    private List<Integer> selectedIndices;
+    private int[] selectedIndices;
 
     /** For button fields: whether it's checked */
     private Boolean checked;

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonImageElement.java

@@ -1,8 +1,5 @@
 package stirling.software.SPDF.model.json;
 
-import java.util.ArrayList;
-import java.util.List;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import lombok.AllArgsConstructor;
@@ -30,7 +27,7 @@ public class PdfJsonImageElement {
     private Float right;
     private Float top;
     private Float bottom;
-    @Builder.Default private List<Float> transform = new ArrayList<>();
+    private float[] transform;
     private Integer zOrder;
     private String imageData;
     private String imageFormat;

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonPageDimension.java

@@ -11,10 +11,10 @@ import lombok.NoArgsConstructor;
 @Builder
 @NoArgsConstructor
 @AllArgsConstructor
-@JsonInclude(JsonInclude.Include.NON_NULL)
+@JsonInclude(JsonInclude.Include.NON_DEFAULT)
 public class PdfJsonPageDimension {
-    private Integer pageNumber;
-    private Float width;
-    private Float height;
-    private Integer rotation;
+    private int pageNumber;
+    private float width;
+    private float height;
+    private int rotation;
 }

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonTextColor.java

@@ -1,7 +1,5 @@
 package stirling.software.SPDF.model.json;
 
-import java.util.List;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import lombok.AllArgsConstructor;
@@ -17,5 +15,5 @@ import lombok.NoArgsConstructor;
 public class PdfJsonTextColor {
 
     private String colorSpace;
-    private List<Float> components;
+    private float[] components;
 }

app/core/src/main/java/stirling/software/SPDF/model/json/PdfJsonTextElement.java

@@ -1,7 +1,5 @@
 package stirling.software.SPDF.model.json;
 
-import java.util.List;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import lombok.AllArgsConstructor;
@@ -32,10 +30,10 @@ public class PdfJsonTextElement {
     private Float y;
     private Float width;
     private Float height;
-    private List<Float> textMatrix;
+    private float[] textMatrix;
     private PdfJsonTextColor fillColor;
     private PdfJsonTextColor strokeColor;
     private Integer renderingMode;
     private Boolean fallbackUsed;
-    private List<Integer> charCodes;
+    private int[] charCodes;
 }

app/core/src/main/java/stirling/software/SPDF/service/PdfJsonConversionService.java

@@ -273,11 +273,11 @@ public class PdfJsonConversionService {
 
         // Get job ID from request context if running in async mode
         String contextJobId = getJobIdFromRequest();
-        boolean isRealJobId = (contextJobId != null && !contextJobId.isEmpty());
+        boolean useLazyImages = (contextJobId != null && !contextJobId.isEmpty());
 
         // Generate synthetic jobId for synchronous conversions to prevent cache collisions
         final String jobId;
-        if (!isRealJobId) {
+        if (!useLazyImages) {
             jobId = "pdf2json:" + java.util.UUID.randomUUID().toString();
             log.debug("Generated synthetic jobId for synchronous conversion: {}", jobId);
         } else {
@@ -302,7 +302,7 @@ public class PdfJsonConversionService {
                                             : "");
                             progressCallback.accept(p);
                         }
-                        : isRealJobId
+                        : useLazyImages
                                 ? (p) -> {
                                     log.debug(
                                             "Progress: [{}%] {} - {}{}",
@@ -369,7 +369,6 @@ public class PdfJsonConversionService {
                 int totalPages = document.getNumberOfPages();
                 // Always enable lazy mode for real async jobs so cache is available regardless of
                 // page count. Synchronous calls with synthetic jobId still do full extraction.
-                boolean useLazyImages = isRealJobId;
                 Map<COSBase, FontModelCacheEntry> fontCache = new IdentityHashMap<>();
                 Map<COSBase, EncodedImage> imageCache = new IdentityHashMap<>();
                 log.debug(
@@ -377,7 +376,7 @@ public class PdfJsonConversionService {
                         totalPages,
                         useLazyImages ? "lazy image" : "standard",
                         jobId,
-                        isRealJobId);
+                        useLazyImages);
                 Map<String, PdfJsonFont> fonts = new LinkedHashMap<>();
                 Map<Integer, List<PdfJsonTextElement>> textByPage = new LinkedHashMap<>();
                 Map<Integer, Map<PDFont, String>> pageFontResources = new HashMap<>();
@@ -431,7 +430,7 @@ public class PdfJsonConversionService {
                 progress.accept(
                         PdfJsonConversionProgress.of(
                                 80, "annotations", "Collecting annotations and form fields"));
-                boolean includeAnnotationRawData = !(lightweight && isRealJobId);
+                boolean includeAnnotationRawData = !(lightweight && useLazyImages);
                 Map<Integer, List<PdfJsonAnnotation>> annotationsByPage =
                         collectAnnotations(
                                 document, totalPages, progress, includeAnnotationRawData);
@@ -463,8 +462,8 @@ public class PdfJsonConversionService {
                                 textByPage,
                                 imagesByPage,
                                 annotationsByPage,
-                                lightweight && isRealJobId));
-                if (lightweight && isRealJobId) {
+                                lightweight && useLazyImages));
+                if (lightweight && useLazyImages) {
                     // Lightweight async editor flow does not use form fields and this payload can
                     // be
                     // very large due nested raw dictionaries.
@@ -474,12 +473,11 @@ public class PdfJsonConversionService {
                 }
 
                 // Only cache for real async jobIds, not synthetic synchronous ones
-                if (useLazyImages && isRealJobId) {
+                if (useLazyImages) {
                     log.debug(
-                            "Creating cache for jobId: {} (useLazyImages={}, isRealJobId={})",
+                            "Creating cache for jobId: {} (useLazyImages={})",
                             jobId,
-                            useLazyImages,
-                            isRealJobId);
+                            useLazyImages);
                     PdfJsonDocumentMetadata docMetadata = new PdfJsonDocumentMetadata();
                     docMetadata.setMetadata(pdfJson.getMetadata());
                     docMetadata.setXmpMetadata(pdfJson.getXmpMetadata());
@@ -529,16 +527,15 @@ public class PdfJsonConversionService {
                     scheduleDocumentCleanup(jobId);
                 } else {
                     log.warn(
-                            "Skipping cache creation: useLazyImages={}, isRealJobId={}, jobId={}",
+                            "Skipping cache creation: useLazyImages={}, jobId={}",
                             useLazyImages,
-                            isRealJobId,
                             jobId);
                 }
 
                 if (lightweight) {
                     applyLightweightTransformations(pdfJson);
                 }
-                if (lightweight && isRealJobId) {
+                if (lightweight && useLazyImages) {
                     stripFontProgramPayloads(responseFonts);
                     stripFontCosStreamData(responseFonts);
                 }
@@ -2503,11 +2500,12 @@ public class PdfJsonConversionService {
                     PDRectangle rect = annotation.getRectangle();
                     if (rect != null) {
                         ann.setRect(
-                                List.of(
-                                        rect.getLowerLeftX(),
-                                        rect.getLowerLeftY(),
-                                        rect.getUpperRightX(),
-                                        rect.getUpperRightY()));
+                                new float[] {
+                                    rect.getLowerLeftX(),
+                                    rect.getLowerLeftY(),
+                                    rect.getUpperRightX(),
+                                    rect.getUpperRightY()
+                                });
                     }
 
                     COSName appearanceState = annotation.getAppearanceState();
@@ -2516,12 +2514,7 @@ public class PdfJsonConversionService {
                     }
 
                     if (annotation.getColor() != null) {
-                        float[] colorComponents = annotation.getColor().getComponents();
-                        List<Float> colorList = new ArrayList<>(colorComponents.length);
-                        for (float c : colorComponents) {
-                            colorList.add(c);
-                        }
-                        ann.setColor(colorList);
+                        ann.setColor(annotation.getColor().getComponents());
                     }
 
                     COSDictionary annotDict = annotation.getCOSObject();
@@ -2636,11 +2629,12 @@ public class PdfJsonConversionService {
                             PDRectangle rect = widget.getRectangle();
                             if (rect != null) {
                                 formField.setRect(
-                                        List.of(
-                                                rect.getLowerLeftX(),
-                                                rect.getLowerLeftY(),
-                                                rect.getUpperRightX(),
-                                                rect.getUpperRightY()));
+                                        new float[] {
+                                            rect.getLowerLeftX(),
+                                            rect.getLowerLeftY(),
+                                            rect.getUpperRightX(),
+                                            rect.getUpperRightY()
+                                        });
                             }
                         }
                     }
@@ -3351,7 +3345,7 @@ public class PdfJsonConversionService {
         PDFont currentFont = baseFont;
         String currentFontId = baseFontId;
 
-        List<Integer> elementCodes = element.getCharCodes();
+        int[] elementCodes = element.getCharCodes();
         int codeIndex = 0;
         boolean rawType3CodesUsed = false;
         int rawType3GlyphCount = 0;
@@ -3363,8 +3357,8 @@ public class PdfJsonConversionService {
             PDFont targetFont = baseFont;
             String targetFontId = baseFontId;
             Integer rawCode = null;
-            if (elementCodes != null && codeIndex < elementCodes.size()) {
-                rawCode = elementCodes.get(codeIndex);
+            if (elementCodes != null && codeIndex < elementCodes.length) {
+                rawCode = elementCodes[codeIndex];
             }
             codeIndex++;
 
@@ -3667,10 +3661,7 @@ public class PdfJsonConversionService {
         if (color == null || color.getComponents() == null) {
             return;
         }
-        float[] components = new float[color.getComponents().size()];
-        for (int i = 0; i < components.length; i++) {
-            components[i] = color.getComponents().get(i);
-        }
+        float[] components = color.getComponents();
         String space = color.getColorSpace();
         if (space == null) {
             // Infer color space from component count
@@ -4287,8 +4278,11 @@ public class PdfJsonConversionService {
         List<Integer> combinedCodes = new ArrayList<>();
         for (PdfJsonTextElement element : elements) {
             builder.append(Objects.toString(element.getText(), ""));
-            if (element.getCharCodes() != null && !element.getCharCodes().isEmpty()) {
-                combinedCodes.addAll(element.getCharCodes());
+            int[] codes = element.getCharCodes();
+            if (codes != null && codes.length > 0) {
+                for (int code : codes) {
+                    combinedCodes.add(code);
+                }
             }
         }
         return new MergedText(builder.toString(), combinedCodes.isEmpty() ? null : combinedCodes);
@@ -4354,9 +4348,9 @@ public class PdfJsonConversionService {
         }
 
         private int countGlyphs(PdfJsonTextElement element) {
-            List<Integer> codes = element.getCharCodes();
-            if (codes != null && !codes.isEmpty()) {
-                return codes.size();
+            int[] codes = element.getCharCodes();
+            if (codes != null && codes.length > 0) {
+                return codes.length;
             }
             String text = element.getText();
             if (text != null && !text.isEmpty()) {
@@ -4920,15 +4914,15 @@ public class PdfJsonConversionService {
 
     private void applyTextMatrix(PDPageContentStream contentStream, PdfJsonTextElement element)
             throws IOException {
-        List<Float> matrix = element.getTextMatrix();
-        if (matrix != null && matrix.size() == 6) {
+        float[] matrix = element.getTextMatrix();
+        if (matrix != null && matrix.length == 6) {
             float fontScale = resolveFontMatrixSize(element);
-            float a = matrix.get(0);
-            float b = matrix.get(1);
-            float c = matrix.get(2);
-            float d = matrix.get(3);
-            float e = matrix.get(4);
-            float f = matrix.get(5);
+            float a = matrix[0];
+            float b = matrix[1];
+            float c = matrix[2];
+            float d = matrix[3];
+            float e = matrix[4];
+            float f = matrix[5];
 
             if (fontScale != 0f) {
                 a /= fontScale;
@@ -4950,12 +4944,12 @@ public class PdfJsonConversionService {
         if (fromElement != null && fromElement > 0f) {
             return fromElement;
         }
-        List<Float> matrix = element.getTextMatrix();
-        if (matrix != null && matrix.size() >= 4) {
-            float a = matrix.get(0);
-            float b = matrix.get(1);
-            float c = matrix.get(2);
-            float d = matrix.get(3);
+        float[] matrix = element.getTextMatrix();
+        if (matrix != null && matrix.length >= 4) {
+            float a = matrix[0];
+            float b = matrix[1];
+            float c = matrix[2];
+            float d = matrix[3];
             float verticalScale = (float) Math.hypot(b, d);
             if (verticalScale > 0f) {
                 return verticalScale;
@@ -5048,7 +5042,7 @@ public class PdfJsonConversionService {
             }
             Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();
             Bounds bounds = computeBounds(ctm);
-            List<Float> matrixValues = toMatrixValues(ctm);
+            float[] matrixValues = toMatrixValues(ctm);
 
             PdfJsonImageElement element =
                     PdfJsonImageElement.builder()
@@ -5222,15 +5216,15 @@ public class PdfJsonConversionService {
 
     private record EncodedImage(String base64, String format) {}
 
-    private List<Float> toMatrixValues(Matrix matrix) {
-        List<Float> values = new ArrayList<>(6);
-        values.add(matrix.getValue(0, 0));
-        values.add(matrix.getValue(0, 1));
-        values.add(matrix.getValue(1, 0));
-        values.add(matrix.getValue(1, 1));
-        values.add(matrix.getValue(2, 0));
-        values.add(matrix.getValue(2, 1));
-        return values;
+    private float[] toMatrixValues(Matrix matrix) {
+        return new float[] {
+            matrix.getValue(0, 0),
+            matrix.getValue(0, 1),
+            matrix.getValue(1, 0),
+            matrix.getValue(1, 1),
+            matrix.getValue(2, 0),
+            matrix.getValue(2, 1)
+        };
     }
 
     private EncodedImage encodeImage(PDImage image) {
@@ -5341,16 +5335,16 @@ public class PdfJsonConversionService {
             cache.put(cacheKey, image);
         }
 
-        List<Float> transform = element.getTransform();
-        if (transform != null && transform.size() == 6) {
+        float[] transform = element.getTransform();
+        if (transform != null && transform.length == 6) {
             Matrix matrix =
                     new Matrix(
-                            safeFloat(transform.get(0), 1f),
-                            safeFloat(transform.get(1), 0f),
-                            safeFloat(transform.get(2), 0f),
-                            safeFloat(transform.get(3), 1f),
-                            safeFloat(transform.get(4), 0f),
-                            safeFloat(transform.get(5), 0f));
+                            safeFloat(transform[0], 1f),
+                            safeFloat(transform[1], 0f),
+                            safeFloat(transform[2], 0f),
+                            safeFloat(transform[3], 1f),
+                            safeFloat(transform[4], 0f),
+                            safeFloat(transform[5], 0f));
             contentStream.drawImage(image, matrix);
             return;
         }
@@ -5516,14 +5510,17 @@ public class PdfJsonConversionService {
             if (pdfont instanceof PDType3Font) {
                 int[] codes = position.getCharacterCodes();
                 if (codes != null && codes.length > 0) {
-                    List<Integer> codeList = new ArrayList<>(codes.length);
+                    int count = 0;
                     for (int code : codes) {
-                        if (code >= 0) {
-                            codeList.add(code);
-                        }
+                        if (code >= 0) count++;
                     }
-                    if (!codeList.isEmpty()) {
-                        element.setCharCodes(codeList);
+                    if (count > 0) {
+                        int[] filtered = new int[count];
+                        int idx = 0;
+                        for (int code : codes) {
+                            if (code >= 0) filtered[idx++] = code;
+                        }
+                        element.setCharCodes(filtered);
                     }
                 }
             }
@@ -5552,11 +5549,11 @@ public class PdfJsonConversionService {
                 return;
             }
 
-            List<Float> matrix = element.getTextMatrix();
+            float[] matrix = element.getTextMatrix();
             if (matrix != null) {
-                if (matrix.isEmpty()) {
+                if (matrix.length == 0) {
                     element.setTextMatrix(null);
-                } else if (matrix.size() == 6) {
+                } else if (matrix.length == 6) {
                     element.setX(null);
                     element.setY(null);
                 }
@@ -5597,29 +5594,29 @@ public class PdfJsonConversionService {
             if (color == null || color.getComponents() == null) {
                 return true;
             }
-            List<Float> components = color.getComponents();
-            if (components.isEmpty()) {
+            float[] components = color.getComponents();
+            if (components.length == 0) {
                 return true;
             }
             String space = color.getColorSpace();
             if (space == null || "DeviceRGB".equals(space)) {
-                if (components.size() < 3) {
+                if (components.length < 3) {
                     return false;
                 }
-                return Math.abs(components.get(0)) < FLOAT_EPSILON
-                        && Math.abs(components.get(1)) < FLOAT_EPSILON
-                        && Math.abs(components.get(2)) < FLOAT_EPSILON;
+                return Math.abs(components[0]) < FLOAT_EPSILON
+                        && Math.abs(components[1]) < FLOAT_EPSILON
+                        && Math.abs(components[2]) < FLOAT_EPSILON;
             }
             if ("DeviceGray".equals(space)) {
-                return Math.abs(components.get(0)) < FLOAT_EPSILON;
+                return Math.abs(components[0]) < FLOAT_EPSILON;
             }
             return false;
         }
 
         private Float baselineFrom(PdfJsonTextElement element) {
-            List<Float> matrix = element.getTextMatrix();
-            if (matrix != null && matrix.size() >= 6) {
-                return matrix.get(5);
+            float[] matrix = element.getTextMatrix();
+            if (matrix != null && matrix.length >= 6) {
+                return matrix[5];
             }
             return element.getY();
         }
@@ -5648,11 +5645,12 @@ public class PdfJsonConversionService {
             private final float orientationC;
             private final float orientationD;
             private final Float baseline;
-            private final List<Float> baseMatrix;
+            private final float[] baseMatrix;
             private final float startXCoord;
             private final float startYCoord;
             private final StringBuilder textBuilder = new StringBuilder();
-            private final List<Integer> charCodeBuffer = new ArrayList<>();
+            private int[] charCodeBuf = new int[16];
+            private int charCodeLen = 0;
             private float totalWidth;
             private float maxHeight;
             private float endXCoord;
@@ -5660,17 +5658,15 @@ public class PdfJsonConversionService {
             TextRunAccumulator(PdfJsonTextElement element, TextPosition position) {
                 this.baseElement = element;
                 this.styleKey = buildStyleKey(element);
-                this.baseMatrix =
-                        element.getTextMatrix() != null
-                                ? new ArrayList<>(element.getTextMatrix())
-                                : null;
-                if (baseMatrix != null && baseMatrix.size() >= 6) {
-                    orientationA = baseMatrix.get(0);
-                    orientationB = baseMatrix.get(1);
-                    orientationC = baseMatrix.get(2);
-                    orientationD = baseMatrix.get(3);
-                    startXCoord = baseMatrix.get(4);
-                    startYCoord = baseMatrix.get(5);
+                float[] tm = element.getTextMatrix();
+                this.baseMatrix = tm != null ? tm.clone() : null;
+                if (baseMatrix != null && baseMatrix.length >= 6) {
+                    orientationA = baseMatrix[0];
+                    orientationB = baseMatrix[1];
+                    orientationC = baseMatrix[2];
+                    orientationD = baseMatrix[3];
+                    startXCoord = baseMatrix[4];
+                    startYCoord = baseMatrix[5];
                 } else {
                     orientationA = 1f;
                     orientationB = 0f;
@@ -5684,25 +5680,23 @@ public class PdfJsonConversionService {
                 this.maxHeight = element.getHeight() != null ? element.getHeight() : 0f;
                 this.endXCoord = position.getXDirAdj() + position.getWidthDirAdj();
                 this.textBuilder.append(element.getText());
-                if (element.getCharCodes() != null) {
-                    charCodeBuffer.addAll(element.getCharCodes());
-                }
+                appendCharCodes(element.getCharCodes());
             }
 
             boolean canAppend(PdfJsonTextElement element, TextPosition position) {
                 if (!styleKey.equals(buildStyleKey(element))) {
                     return false;
                 }
-                List<Float> matrix = element.getTextMatrix();
+                float[] matrix = element.getTextMatrix();
                 float a = 1f;
                 float b = 0f;
                 float c = 0f;
                 float d = 1f;
-                if (matrix != null && matrix.size() >= 4) {
-                    a = matrix.get(0);
-                    b = matrix.get(1);
-                    c = matrix.get(2);
-                    d = matrix.get(3);
+                if (matrix != null && matrix.length >= 4) {
+                    a = matrix[0];
+                    b = matrix[1];
+                    c = matrix[2];
+                    d = matrix[3];
                 }
                 if (Math.abs(a - orientationA) > ORIENTATION_TOLERANCE
                         || Math.abs(b - orientationB) > ORIENTATION_TOLERANCE
@@ -5734,9 +5728,19 @@ public class PdfJsonConversionService {
                     maxHeight = height;
                 }
                 endXCoord = position.getXDirAdj() + position.getWidthDirAdj();
-                if (element.getCharCodes() != null) {
-                    charCodeBuffer.addAll(element.getCharCodes());
+                appendCharCodes(element.getCharCodes());
+            }
+
+            private void appendCharCodes(int[] codes) {
+                if (codes == null) return;
+                int needed = charCodeLen + codes.length;
+                if (needed > charCodeBuf.length) {
+                    charCodeBuf =
+                            java.util.Arrays.copyOf(
+                                    charCodeBuf, Math.max(needed, charCodeBuf.length * 2));
                 }
+                System.arraycopy(codes, 0, charCodeBuf, charCodeLen, codes.length);
+                charCodeLen += codes.length;
             }
 
             PdfJsonTextElement build() {
@@ -5748,22 +5752,21 @@ public class PdfJsonConversionService {
                 }
                 result.setWidth(totalWidth);
                 result.setHeight(maxHeight);
-                if (baseMatrix != null && baseMatrix.size() == 6) {
-                    List<Float> matrix = new ArrayList<>(baseMatrix);
-                    matrix.set(0, orientationA);
-                    matrix.set(1, orientationB);
-                    matrix.set(2, orientationC);
-                    matrix.set(3, orientationD);
-                    matrix.set(4, startXCoord);
-                    matrix.set(5, startYCoord);
+                if (baseMatrix != null && baseMatrix.length == 6) {
+                    float[] matrix =
+                            new float[] {
+                                orientationA, orientationB,
+                                orientationC, orientationD,
+                                startXCoord, startYCoord
+                            };
                     result.setTextMatrix(matrix);
                     result.setX(null);
                     result.setY(null);
                 }
-                if (charCodeBuffer.isEmpty()) {
+                if (charCodeLen == 0) {
                     result.setCharCodes(null);
                 } else {
-                    result.setCharCodes(new ArrayList<>(charCodeBuffer));
+                    result.setCharCodes(java.util.Arrays.copyOf(charCodeBuf, charCodeLen));
                 }
                 compactTextElement(result);
                 return result;
@@ -5784,29 +5787,25 @@ public class PdfJsonConversionService {
                 Integer renderingMode,
                 Float spaceWidth) {}
 
-        private List<Float> extractMatrix(TextPosition position) {
-            float[] values = new float[6];
-            values[0] = position.getTextMatrix().getValue(0, 0);
-            values[1] = position.getTextMatrix().getValue(0, 1);
-            values[2] = position.getTextMatrix().getValue(1, 0);
-            values[3] = position.getTextMatrix().getValue(1, 1);
-            values[4] = position.getTextMatrix().getValue(2, 0);
-            values[5] = position.getTextMatrix().getValue(2, 1);
-            List<Float> matrix = new ArrayList<>(6);
-            for (float value : values) {
-                matrix.add(value);
-            }
-            return matrix;
+        private float[] extractMatrix(TextPosition position) {
+            return new float[] {
+                position.getTextMatrix().getValue(0, 0),
+                position.getTextMatrix().getValue(0, 1),
+                position.getTextMatrix().getValue(1, 0),
+                position.getTextMatrix().getValue(1, 1),
+                position.getTextMatrix().getValue(2, 0),
+                position.getTextMatrix().getValue(2, 1)
+            };
         }
 
-        private Float computeFontMatrixSize(List<Float> matrix) {
-            if (matrix == null || matrix.size() < 4) {
+        private Float computeFontMatrixSize(float[] matrix) {
+            if (matrix == null || matrix.length < 4) {
                 return null;
             }
-            float a = matrix.get(0);
-            float b = matrix.get(1);
-            float c = matrix.get(2);
-            float d = matrix.get(3);
+            float a = matrix[0];
+            float b = matrix[1];
+            float c = matrix[2];
+            float d = matrix[3];
             float scaleX = (float) Math.hypot(a, c);
             float scaleY = (float) Math.hypot(b, d);
             float scale = Math.max(scaleX, scaleY);
@@ -5850,11 +5849,10 @@ public class PdfJsonConversionService {
                         colorSpaceName,
                         ex.getMessage());
             }
-            List<Float> values = new ArrayList<>(effective.length);
-            for (float component : effective) {
-                values.add(component);
-            }
-            return PdfJsonTextColor.builder().colorSpace(colorSpaceName).components(values).build();
+            return PdfJsonTextColor.builder()
+                    .colorSpace(colorSpaceName)
+                    .components(effective)
+                    .build();
         }
 
         private String sanitizeForLog(String value) {
@@ -6241,11 +6239,12 @@ public class PdfJsonConversionService {
                     PDRectangle rect = annotation.getRectangle();
                     if (rect != null) {
                         ann.setRect(
-                                List.of(
-                                        rect.getLowerLeftX(),
-                                        rect.getLowerLeftY(),
-                                        rect.getUpperRightX(),
-                                        rect.getUpperRightY()));
+                                new float[] {
+                                    rect.getLowerLeftX(),
+                                    rect.getLowerLeftY(),
+                                    rect.getUpperRightX(),
+                                    rect.getUpperRightY()
+                                });
                     }
 
                     COSName appearanceState = annotation.getAppearanceState();
@@ -6254,12 +6253,7 @@ public class PdfJsonConversionService {
                     }
 
                     if (annotation.getColor() != null) {
-                        float[] colorComponents = annotation.getColor().getComponents();
-                        List<Float> colorList = new ArrayList<>(colorComponents.length);
-                        for (float c : colorComponents) {
-                            colorList.add(c);
-                        }
-                        ann.setColor(colorList);
+                        ann.setColor(annotation.getColor().getComponents());
                     }
 
                     COSDictionary annotDict = annotation.getCOSObject();

app/core/src/main/java/stirling/software/SPDF/service/SharedSignatureService.java

@@ -30,7 +30,7 @@ public class SharedSignatureService {
 
     private static final Pattern FILENAME_VALIDATION_PATTERN = Pattern.compile("^[a-zA-Z0-9_.-]+$");
     private final String SIGNATURE_BASE_PATH;
-    private final String ALL_USERS_FOLDER = "ALL_USERS";
+    private static final String ALL_USERS_FOLDER = "ALL_USERS";
     private final ObjectMapper objectMapper;
 
     public SharedSignatureService(ObjectMapper objectMapper) {
@@ -159,12 +159,12 @@ public class SharedSignatureService {
         String dataUrl = request.getDataUrl();
         if (dataUrl != null && dataUrl.startsWith("data:image/")) {
             // Extract base64 data
-            String base64Data = dataUrl.substring(dataUrl.indexOf(",") + 1);
+            String base64Data = dataUrl.substring(dataUrl.indexOf(',') + 1);
             byte[] imageBytes = Base64.getDecoder().decode(base64Data);
 
             // Determine and validate file extension from data URL
-            String mimeType = dataUrl.substring(dataUrl.indexOf(":") + 1, dataUrl.indexOf(";"));
-            String rawExtension = mimeType.substring(mimeType.indexOf("/") + 1);
+            String mimeType = dataUrl.substring(dataUrl.indexOf(':') + 1, dataUrl.indexOf(';'));
+            String rawExtension = mimeType.substring(mimeType.indexOf('/') + 1);
             String extension = validateAndNormalizeExtension(rawExtension);
 
             // Save image file only

app/core/src/main/java/stirling/software/SPDF/service/pdfjson/PdfJsonImageService.java

@@ -134,16 +134,16 @@ public class PdfJsonImageService {
             cache.put(cacheKey, image);
         }
 
-        List<Float> transform = element.getTransform();
-        if (transform != null && transform.size() == 6) {
+        float[] transform = element.getTransform();
+        if (transform != null && transform.length == 6) {
             Matrix matrix =
                     new Matrix(
-                            safeFloat(transform.get(0), 1f),
-                            safeFloat(transform.get(1), 0f),
-                            safeFloat(transform.get(2), 0f),
-                            safeFloat(transform.get(3), 1f),
-                            safeFloat(transform.get(4), 0f),
-                            safeFloat(transform.get(5), 0f));
+                            safeFloat(transform[0], 1f),
+                            safeFloat(transform[1], 0f),
+                            safeFloat(transform[2], 0f),
+                            safeFloat(transform[3], 1f),
+                            safeFloat(transform[4], 0f),
+                            safeFloat(transform[5], 0f));
             contentStream.drawImage(image, matrix);
             return;
         }
@@ -269,18 +269,18 @@ public class PdfJsonImageService {
         return 0f;
     }
 
-    private List<Float> toMatrixValues(Matrix matrix) {
-        List<Float> values = new ArrayList<>(6);
-        values.add(matrix.getValue(0, 0));
-        values.add(matrix.getValue(0, 1));
-        values.add(matrix.getValue(1, 0));
-        values.add(matrix.getValue(1, 1));
-        values.add(matrix.getValue(2, 0));
-        values.add(matrix.getValue(2, 1));
-        return values;
+    private float[] toMatrixValues(Matrix matrix) {
+        return new float[] {
+            matrix.getValue(0, 0),
+            matrix.getValue(0, 1),
+            matrix.getValue(1, 0),
+            matrix.getValue(1, 1),
+            matrix.getValue(2, 0),
+            matrix.getValue(2, 1)
+        };
     }
 
-    private float safeFloat(Float value, float defaultValue) {
+    private static float safeFloat(Float value, float defaultValue) {
         if (value == null || Float.isNaN(value) || Float.isInfinite(value)) {
             return defaultValue;
         }
@@ -324,7 +324,7 @@ public class PdfJsonImageService {
             }
             Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();
             Bounds bounds = computeBounds(ctm);
-            List<Float> matrixValues = toMatrixValues(ctm);
+            float[] matrixValues = toMatrixValues(ctm);
 
             PdfJsonImageElement element =
                     PdfJsonImageElement.builder()

app/core/src/main/java/stirling/software/SPDF/service/pdfjson/type3/Type3LibraryStrategy.java

@@ -110,7 +110,12 @@ public class Type3LibraryStrategy implements Type3ConversionStrategy {
                 .webProgramFormat(toFormat(entry.getWebProgram()))
                 .pdfProgram(toBase64(entry.getPdfProgram()))
                 .pdfProgramFormat(toFormat(entry.getPdfProgram()))
-                .glyphCoverage(entry.getGlyphCoverage())
+                .glyphCoverage(
+                        entry.getGlyphCoverage() != null
+                                ? entry.getGlyphCoverage().stream()
+                                        .mapToInt(Integer::intValue)
+                                        .toArray()
+                                : null)
                 .message(message)
                 .build();
     }

app/core/src/main/resources/application.properties

@@ -1,4 +1,9 @@
 multipart.enabled=true
+
+# Jackson 3 defaults FAIL_ON_NULL_FOR_PRIMITIVES to true (was false in Jackson 2).
+# Restore Jackson 2 behaviour so absent/null JSON fields map to Java primitive defaults.
+spring.jackson.deserialization.fail-on-null-for-primitives=false
+
 logging.level.org.springframework=WARN
 logging.level.org.springframework.security=WARN
 logging.level.org.hibernate=WARN
@@ -25,14 +30,16 @@ server.compression.enabled=true
 server.compression.min-response-size=1024
 server.compression.mime-types=application/json,application/xml,text/html,text/plain,text/css,application/javascript
 
-server.error.path=/error
-server.error.whitelabel.enabled=false
-server.error.include-stacktrace=always
-server.error.include-exception=true
-server.error.include-message=always
+spring.web.error.path=/error
+spring.web.error.whitelabel.enabled=false
+spring.web.error.include-stacktrace=always
+spring.web.error.include-exception=true
+spring.web.error.include-message=always
 
-# Enable RFC 7807 Problem Details for HTTP APIs
-spring.mvc.problemdetails.enabled=true
+# Disable Spring's built-in ProblemDetailsExceptionHandler (@Order(0)) so that
+# GlobalExceptionHandler runs first and provides detailed, logged error responses.
+# GlobalExceptionHandler already produces RFC 7807 ProblemDetail objects.
+spring.mvc.problemdetails.enabled=false
 
 #logging.level.org.springframework.web=DEBUG
 #logging.level.org.springframework=DEBUG

app/core/src/test/java/stirling/software/SPDF/controller/api/SplitPdfBySizeControllerTest.java

@@ -25,6 +25,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.mock.web.MockMultipartFile;
+import org.springframework.web.multipart.MultipartFile;
 
 import stirling.software.SPDF.model.api.general.SplitPdfBySizeOrCountRequest;
 import stirling.software.common.service.CustomPDFDocumentFactory;
@@ -69,16 +70,15 @@ class SplitPdfBySizeControllerTest {
         request.setSplitType(1); // Page count
         request.setSplitValue("2");
 
-        when(pdfDocumentFactory.load(any(byte[].class)))
-                .thenAnswer(inv -> Loader.loadPDF((byte[]) inv.getArgument(0)));
+        when(pdfDocumentFactory.load(any(MultipartFile.class)))
+                .thenAnswer(inv -> Loader.loadPDF(((MultipartFile) inv.getArgument(0)).getBytes()));
 
         when(pdfDocumentFactory.createNewDocumentBasedOnOldDocument(any(PDDocument.class)))
                 .thenAnswer(inv -> new PDDocument());
 
-        ResponseEntity<byte[]> response = controller.autoSplitPdf(request);
+        ResponseEntity<?> response = controller.autoSplitPdf(request);
 
         assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
-        assertThat(response.getBody()).isNotEmpty();
         assertThat(response.getHeaders().getContentType())
                 .isEqualTo(MediaType.APPLICATION_OCTET_STREAM);
     }
@@ -104,15 +104,19 @@ class SplitPdfBySizeControllerTest {
         request.setSplitType(2); // Document count
         request.setSplitValue("3"); // Split into 3 docs (2 pages each)
 
-        when(pdfDocumentFactory.load(any(byte[].class)))
-                .thenAnswer(inv -> Loader.loadPDF((byte[]) inv.getArgument(0)));
+        when(pdfDocumentFactory.load(any(org.springframework.web.multipart.MultipartFile.class)))
+                .thenAnswer(
+                        inv ->
+                                Loader.loadPDF(
+                                        ((org.springframework.web.multipart.MultipartFile)
+                                                        inv.getArgument(0))
+                                                .getBytes()));
 
         when(pdfDocumentFactory.createNewDocumentBasedOnOldDocument(any(PDDocument.class)))
                 .thenAnswer(inv -> new PDDocument());
 
-        ResponseEntity<byte[]> response = controller.autoSplitPdf(request);
+        ResponseEntity<?> response = controller.autoSplitPdf(request);
 
         assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
-        assertThat(response.getBody()).isNotEmpty();
     }
 }

app/core/src/test/java/stirling/software/SPDF/controller/api/converters/PdfToCbzUtilsTest.java

@@ -13,10 +13,12 @@ import org.springframework.mock.web.MockMultipartFile;
 
 import stirling.software.common.service.CustomPDFDocumentFactory;
 import stirling.software.common.util.PdfToCbzUtils;
+import stirling.software.common.util.TempFileManager;
 
 public class PdfToCbzUtilsTest {
 
     @Mock private CustomPDFDocumentFactory pdfDocumentFactory;
+    @Mock private TempFileManager tempFileManager;
 
     @BeforeEach
     public void setUp() {
@@ -42,7 +44,9 @@ public class PdfToCbzUtilsTest {
         IllegalArgumentException exception =
                 Assertions.assertThrows(
                         IllegalArgumentException.class,
-                        () -> PdfToCbzUtils.convertPdfToCbz(null, 300, pdfDocumentFactory));
+                        () ->
+                                PdfToCbzUtils.convertPdfToCbz(
+                                        null, 300, pdfDocumentFactory, tempFileManager));
         Assertions.assertEquals("File cannot be null or empty", exception.getMessage());
     }
 
@@ -54,7 +58,9 @@ public class PdfToCbzUtilsTest {
         IllegalArgumentException exception =
                 Assertions.assertThrows(
                         IllegalArgumentException.class,
-                        () -> PdfToCbzUtils.convertPdfToCbz(emptyFile, 300, pdfDocumentFactory));
+                        () ->
+                                PdfToCbzUtils.convertPdfToCbz(
+                                        emptyFile, 300, pdfDocumentFactory, tempFileManager));
         Assertions.assertEquals("File cannot be null or empty", exception.getMessage());
     }
 
@@ -66,7 +72,9 @@ public class PdfToCbzUtilsTest {
         IllegalArgumentException exception =
                 Assertions.assertThrows(
                         IllegalArgumentException.class,
-                        () -> PdfToCbzUtils.convertPdfToCbz(nonPdfFile, 300, pdfDocumentFactory));
+                        () ->
+                                PdfToCbzUtils.convertPdfToCbz(
+                                        nonPdfFile, 300, pdfDocumentFactory, tempFileManager));
         Assertions.assertEquals("File must be in PDF format", exception.getMessage());
     }
 
@@ -84,7 +92,9 @@ public class PdfToCbzUtilsTest {
         // structure
         Assertions.assertThrows(
                 Exception.class,
-                () -> PdfToCbzUtils.convertPdfToCbz(pdfFile, 300, pdfDocumentFactory));
+                () ->
+                        PdfToCbzUtils.convertPdfToCbz(
+                                pdfFile, 300, pdfDocumentFactory, tempFileManager));
 
         // Verify that load was called
         Mockito.verify(pdfDocumentFactory).load(pdfFile);

app/core/src/test/java/stirling/software/SPDF/service/PdfMetadataServiceBasicTest.java

@@ -27,7 +27,7 @@ import stirling.software.common.service.UserServiceInterface;
 class PdfMetadataServiceBasicTest {
 
     private PdfMetadataService pdfMetadataService;
-    private final String STIRLING_PDF_LABEL = "Stirling PDF";
+    private static final String STIRLING_PDF_LABEL = "Stirling PDF";
 
     @BeforeEach
     void setUp() {

app/core/src/test/java/stirling/software/SPDF/service/PdfMetadataServiceTest.java

@@ -33,7 +33,7 @@ class PdfMetadataServiceTest {
     @Mock private ApplicationProperties applicationProperties;
     @Mock private UserServiceInterface userService;
     private PdfMetadataService pdfMetadataService;
-    private final String STIRLING_PDF_LABEL = "Stirling PDF";
+    private static final String STIRLING_PDF_LABEL = "Stirling PDF";
 
     @BeforeEach
     void setUp() {

app/core/src/test/java/stirling/software/SPDF/service/SignatureServiceTest.java

@@ -28,8 +28,8 @@ class SignatureServiceTest {
     private SharedSignatureService signatureService;
     private Path personalSignatureFolder;
     private Path sharedSignatureFolder;
-    private final String ALL_USERS_FOLDER = "ALL_USERS";
-    private final String TEST_USER = "testUser";
+    private static final String ALL_USERS_FOLDER = "ALL_USERS";
+    private static final String TEST_USER = "testUser";
 
     @BeforeEach
     void setUp() throws IOException {

app/proprietary/src/main/java/stirling/software/proprietary/audit/AuditEventType.java

@@ -49,7 +49,7 @@ public enum AuditEventType {
             // If the exact enum name doesn't match, try finding a similar one
             for (AuditEventType eventType : values()) {
                 if (eventType.name().equalsIgnoreCase(type)
-                        || eventType.getDescription().equalsIgnoreCase(type)) {
+                        || eventType.description.equalsIgnoreCase(type)) {
                     return eventType;
                 }
             }

app/proprietary/src/main/java/stirling/software/proprietary/service/SignatureService.java

@@ -35,7 +35,7 @@ public class SignatureService implements PersonalSignatureServiceInterface {
 
     private static final Pattern FILENAME_VALIDATION_PATTERN = Pattern.compile("^[a-zA-Z0-9_.-]+$");
     private final String SIGNATURE_BASE_PATH;
-    private final String ALL_USERS_FOLDER = "ALL_USERS";
+    private static final String ALL_USERS_FOLDER = "ALL_USERS";
     private final ObjectMapper objectMapper;
 
     // Storage limits per user
@@ -115,7 +115,7 @@ public class SignatureService implements PersonalSignatureServiceInterface {
             }
 
             // Extract base64 data
-            String base64Data = dataUrl.substring(dataUrl.indexOf(",") + 1);
+            String base64Data = dataUrl.substring(dataUrl.indexOf(',') + 1);
             byte[] imageBytes = Base64.getDecoder().decode(base64Data);
 
             // Validate decoded size
@@ -127,8 +127,8 @@ public class SignatureService implements PersonalSignatureServiceInterface {
             }
 
             // Determine and validate file extension from data URL
-            String mimeType = dataUrl.substring(dataUrl.indexOf(":") + 1, dataUrl.indexOf(";"));
-            String rawExtension = mimeType.substring(mimeType.indexOf("/") + 1);
+            String mimeType = dataUrl.substring(dataUrl.indexOf(':') + 1, dataUrl.indexOf(';'));
+            String rawExtension = mimeType.substring(mimeType.indexOf('/') + 1);
             String extension = validateAndNormalizeExtension(rawExtension);
 
             // Save image file