feat(cbz-to-pdf,pdf-to-cbz): Converter for CBZ format to and from PDF (#4472)

2026-07-14 10:34:06 +02:00 · 2025-09-28 21:41:50 +01:00
parent 413cd0c697
commit 51aa03b256
12 changed files with 737 additions and 2 deletions
@@ -0,0 +1,201 @@
+package stirling.software.common.util;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.regex.Pattern;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+import java.util.zip.ZipInputStream;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Slf4j
+@UtilityClass
+public class CbzUtils {
+
+    private final Pattern IMAGE_PATTERN =
+            Pattern.compile(".*\\.(jpg|jpeg|png|gif|bmp|webp)$", Pattern.CASE_INSENSITIVE);
+
+    public byte[] convertCbzToPdf(
+            MultipartFile cbzFile,
+            CustomPDFDocumentFactory pdfDocumentFactory,
+            TempFileManager tempFileManager)
+            throws IOException {
+
+        validateCbzFile(cbzFile);
+
+        try (TempFile tempFile = new TempFile(tempFileManager, ".cbz")) {
+            cbzFile.transferTo(tempFile.getFile());
+
+            // Early ZIP validity check using ZipInputStream (fail fast on non-zip content)
+            try (BufferedInputStream bis =
+                            new BufferedInputStream(
+                                    new java.io.FileInputStream(tempFile.getFile()));
+                    ZipInputStream zis = new ZipInputStream(bis)) {
+                if (zis.getNextEntry() == null) {
+                    throw new IllegalArgumentException("Archive is empty or invalid ZIP");
+                }
+            } catch (IOException e) {
+                throw new IllegalArgumentException("Invalid CBZ/ZIP archive", e);
+            }
+
+            try (PDDocument document = pdfDocumentFactory.createNewDocument();
+                    ZipFile zipFile = new ZipFile(tempFile.getFile())) {
+                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());
+                        }
+                    }
+                }
+
+                imageEntries.sort(
+                        Comparator.comparing(ImageEntryData::name, new NaturalOrderComparator()));
+
+                if (imageEntries.isEmpty()) {
+                    throw new IllegalArgumentException("No valid images found in the CBZ file");
+                }
+
+                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)) {
+                            contentStream.drawImage(pdImage, 0, 0);
+                        }
+                    } catch (IOException e) {
+                        log.warn(
+                                "Error processing image {}: {}", imageEntry.name(), e.getMessage());
+                    }
+                }
+
+                if (document.getNumberOfPages() == 0) {
+                    throw new IllegalArgumentException(
+                            "No images could be processed from the CBZ file");
+                }
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                document.save(baos);
+                return baos.toByteArray();
+            }
+        }
+    }
+
+    private void validateCbzFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"cbz".equals(extension) && !"zip".equals(extension)) {
+            throw new IllegalArgumentException("File must be a CBZ or ZIP archive");
+        }
+    }
+
+    public boolean isCbzFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "cbz".equals(extension) || "zip".equals(extension);
+    }
+
+    private boolean isImageFile(String filename) {
+        return IMAGE_PATTERN.matcher(filename).matches();
+    }
+
+    private record ImageEntryData(String name, byte[] data) {}
+
+    private class NaturalOrderComparator implements Comparator<String> {
+        @Override
+        public int compare(String s1, String s2) {
+            int len1 = s1.length();
+            int len2 = s2.length();
+            int marker1 = 0, marker2 = 0;
+
+            while (marker1 < len1 && marker2 < len2) {
+                String chunk1 = getChunk(s1, len1, marker1);
+                marker1 += chunk1.length();
+
+                String chunk2 = getChunk(s2, len2, marker2);
+                marker2 += chunk2.length();
+
+                int result;
+                if (isDigit(chunk1.charAt(0)) && isDigit(chunk2.charAt(0))) {
+                    int thisNumericValue = Integer.parseInt(chunk1);
+                    int thatNumericValue = Integer.parseInt(chunk2);
+                    result = Integer.compare(thisNumericValue, thatNumericValue);
+                } else {
+                    result = chunk1.compareTo(chunk2);
+                }
+
+                if (result != 0) {
+                    return result;
+                }
+            }
+
+            return Integer.compare(len1, len2);
+        }
+
+        private static String getChunk(String s, int length, int marker) {
+            StringBuilder chunk = new StringBuilder();
+            char c = s.charAt(marker);
+            chunk.append(c);
+            marker++;
+
+            if (isDigit(c)) {
+                while (marker < length && isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            } else {
+                while (marker < length && !isDigit(s.charAt(marker))) {
+                    chunk.append(s.charAt(marker));
+                    marker++;
+                }
+            }
+            return chunk.toString();
+        }
+
+        private static boolean isDigit(char ch) {
+            return ch >= '0' && ch <= '9';
+        }
+    }
+}
@@ -0,0 +1,99 @@
+package stirling.software.common.util;
+
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import javax.imageio.ImageIO;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.rendering.ImageType;
+import org.apache.pdfbox.rendering.PDFRenderer;
+import org.springframework.web.multipart.MultipartFile;
+
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+
+@Slf4j
+public class PdfToCbzUtils {
+
+    public static byte[] convertPdfToCbz(
+            MultipartFile pdfFile, int dpi, CustomPDFDocumentFactory pdfDocumentFactory)
+            throws IOException {
+
+        validatePdfFile(pdfFile);
+
+        try (PDDocument document = pdfDocumentFactory.load(pdfFile)) {
+            if (document.getNumberOfPages() == 0) {
+                throw new IllegalArgumentException("PDF file contains no pages");
+            }
+
+            return createCbzFromPdf(document, dpi);
+        }
+    }
+
+    private static void validatePdfFile(MultipartFile file) {
+        if (file == null || file.isEmpty()) {
+            throw new IllegalArgumentException("File cannot be null or empty");
+        }
+
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            throw new IllegalArgumentException("File must have a name");
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        if (!"pdf".equals(extension)) {
+            throw new IllegalArgumentException("File must be a PDF");
+        }
+    }
+
+    private static byte[] createCbzFromPdf(PDDocument document, int dpi) throws IOException {
+        PDFRenderer pdfRenderer = new PDFRenderer(document);
+
+        try (ByteArrayOutputStream cbzOutputStream = new ByteArrayOutputStream();
+                ZipOutputStream zipOut = new ZipOutputStream(cbzOutputStream)) {
+
+            int totalPages = document.getNumberOfPages();
+
+            for (int pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+                try {
+                    BufferedImage image =
+                            pdfRenderer.renderImageWithDPI(pageIndex, dpi, ImageType.RGB);
+
+                    String imageFilename = String.format("page_%03d.png", pageIndex + 1);
+
+                    ZipEntry zipEntry = new ZipEntry(imageFilename);
+                    zipOut.putNextEntry(zipEntry);
+
+                    ImageIO.write(image, "PNG", zipOut);
+                    zipOut.closeEntry();
+
+                } catch (IOException e) {
+                    log.warn("Error processing page {}: {}", pageIndex + 1, e.getMessage());
+                } catch (OutOfMemoryError e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                } catch (NegativeArraySizeException e) {
+                    throw ExceptionUtils.createOutOfMemoryDpiException(pageIndex + 1, dpi, e);
+                }
+            }
+
+            zipOut.finish();
+            return cbzOutputStream.toByteArray();
+        }
+    }
+
+    public static boolean isPdfFile(MultipartFile file) {
+        String filename = file.getOriginalFilename();
+        if (filename == null) {
+            return false;
+        }
+
+        String extension = FilenameUtils.getExtension(filename).toLowerCase();
+        return "pdf".equals(extension);
+    }
+}
@@ -8,6 +8,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Pattern;
 import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
@@ -16,6 +17,7 @@ import org.apache.commons.io.FileUtils;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDPage;
 import org.apache.pdfbox.rendering.ImageType;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
@@ -30,11 +32,22 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;

+import stirling.software.SPDF.model.api.converters.ConvertCbzToPdfRequest;
+import stirling.software.SPDF.model.api.converters.ConvertPdfToCbzRequest;
 import stirling.software.SPDF.model.api.converters.ConvertToImageRequest;
 import stirling.software.SPDF.model.api.converters.ConvertToPdfRequest;
 import stirling.software.common.service.CustomPDFDocumentFactory;
-import stirling.software.common.util.*;
+import stirling.software.common.util.CbzUtils;
+import stirling.software.common.util.CheckProgramInstall;
+import stirling.software.common.util.ExceptionUtils;
+import stirling.software.common.util.GeneralUtils;
+import stirling.software.common.util.PdfToCbzUtils;
+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.TempFileManager;
+import stirling.software.common.util.WebResponseUtils;

@RestController
@RequestMapping("/api/v1/convert")
@@ -44,6 +57,10 @@ import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
 public class ConvertImgPDFController {

    private final CustomPDFDocumentFactory pdfDocumentFactory;
+    private final TempFileManager tempFileManager;
+    private static final Pattern EXTENSION_PATTERN =
+            RegexPatternUtils.getInstance().getPattern(RegexPatternUtils.getExtensionRegex());
+    private static final String DEFAULT_COMIC_NAME = "comic";

    @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/pdf/img")
    @Operation(
@@ -234,6 +251,74 @@ public class ConvertImgPDFController {
                GeneralUtils.generateFilename(file[0].getOriginalFilename(), "_converted.pdf"));
    }

+    @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/cbz/pdf")
+    @Operation(
+            summary = "Convert CBZ comic book archive to PDF",
+            description =
+                    "This endpoint converts a CBZ (ZIP) comic book archive to a PDF file. "
+                            + "Input:CBZ Output:PDF Type:SISO")
+    public ResponseEntity<byte[]> convertCbzToPdf(@ModelAttribute ConvertCbzToPdfRequest request)
+            throws IOException {
+        MultipartFile file = request.getFileInput();
+        byte[] pdfBytes;
+        try {
+            pdfBytes = CbzUtils.convertCbzToPdf(file, pdfDocumentFactory, tempFileManager);
+        } catch (IllegalArgumentException ex) {
+            String message = ex.getMessage() == null ? "Invalid CBZ file" : ex.getMessage();
+            return ResponseEntity.status(HttpStatus.BAD_REQUEST)
+                    .contentType(MediaType.TEXT_PLAIN)
+                    .body(message.getBytes(java.nio.charset.StandardCharsets.UTF_8));
+        }
+
+        String filename = createConvertedFilename(file.getOriginalFilename(), "_converted.pdf");
+
+        return WebResponseUtils.bytesToWebResponse(pdfBytes, filename);
+    }
+
+    @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, value = "/pdf/cbz")
+    @Operation(
+            summary = "Convert PDF to CBZ comic book archive",
+            description =
+                    "This endpoint converts a PDF file to a CBZ (ZIP) comic book archive. "
+                            + "Input:PDF Output:CBZ Type:SISO")
+    public ResponseEntity<byte[]> convertPdfToCbz(@ModelAttribute ConvertPdfToCbzRequest request)
+            throws IOException {
+        MultipartFile file = request.getFileInput();
+        Integer dpi = request.getDpi();
+
+        if (dpi == null || dpi <= 0) {
+            dpi = 300;
+        }
+
+        byte[] cbzBytes;
+        try {
+            cbzBytes = PdfToCbzUtils.convertPdfToCbz(file, dpi, pdfDocumentFactory);
+        } catch (IllegalArgumentException ex) {
+            String message = ex.getMessage() == null ? "Invalid PDF file" : ex.getMessage();
+            return ResponseEntity.status(HttpStatus.BAD_REQUEST)
+                    .contentType(MediaType.TEXT_PLAIN)
+                    .body(message.getBytes(java.nio.charset.StandardCharsets.UTF_8));
+        }
+
+        String filename = createConvertedFilename(file.getOriginalFilename(), "_converted.cbz");
+
+        return WebResponseUtils.bytesToWebResponse(
+                cbzBytes, filename, MediaType.APPLICATION_OCTET_STREAM);
+    }
+
+    private String createConvertedFilename(String originalFilename, String suffix) {
+        if (originalFilename == null) {
+            return GeneralUtils.generateFilename(DEFAULT_COMIC_NAME, suffix);
+        }
+
+        String baseName = EXTENSION_PATTERN.matcher(originalFilename).replaceFirst("");
+        if (baseName.isBlank()) {
+            baseName = DEFAULT_COMIC_NAME;
+        }
+
+        return GeneralUtils.generateFilename(baseName, suffix);
+    }
+
    private String getMediaType(String imageFormat) {
        String mimeType = URLConnection.guessContentTypeFromName("." + imageFormat);
        return "null".equals(mimeType) ? MediaType.APPLICATION_OCTET_STREAM_VALUE : mimeType;
@@ -23,6 +23,20 @@ public class ConverterWebController {
        return "convert/img-to-pdf";
    }

+    @GetMapping("/cbz-to-pdf")
+    @Hidden
+    public String convertCbzToPdfForm(Model model) {
+        model.addAttribute("currentPage", "cbz-to-pdf");
+        return "convert/cbz-to-pdf";
+    }
+
+    @GetMapping("/pdf-to-cbz")
+    @Hidden
+    public String convertPdfToCbzForm(Model model) {
+        model.addAttribute("currentPage", "pdf-to-cbz");
+        return "convert/pdf-to-cbz";
+    }
+
    @GetMapping("/html-to-pdf")
    @Hidden
    public String convertHTMLToPdfForm(Model model) {
@@ -0,0 +1,18 @@
+package stirling.software.SPDF.model.api.converters;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Data
+@EqualsAndHashCode
+public class ConvertCbzToPdfRequest {
+
+    @Schema(
+            description = "The input CBZ file to be converted to a PDF file",
+            requiredMode = Schema.RequiredMode.REQUIRED)
+    private MultipartFile fileInput;
+}
@@ -0,0 +1,24 @@
+package stirling.software.SPDF.model.api.converters;
+
+import org.springframework.web.multipart.MultipartFile;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Data
+@EqualsAndHashCode
+public class ConvertPdfToCbzRequest {
+
+    @Schema(
+            description = "The input PDF file to be converted to a CBZ file",
+            requiredMode = Schema.RequiredMode.REQUIRED)
+    private MultipartFile fileInput;
+
+    @Schema(
+            description = "The DPI (Dots Per Inch) for rendering PDF pages as images",
+            example = "300",
+            requiredMode = Schema.RequiredMode.NOT_REQUIRED)
+    private Integer dpi = 300;
+}
@@ -606,6 +606,14 @@ home.imageToPdf.title=Image to PDF
 home.imageToPdf.desc=Convert a image (PNG, JPEG, GIF, PSD) to PDF.
 imageToPdf.tags=conversion,img,jpg,picture,photo,psd,photoshop

+home.cbzToPdf.title=CBZ to PDF
+home.cbzToPdf.desc=Convert CBZ comic book archives to PDF format.
+cbzToPdf.tags=conversion,comic,book,archive,cbz,zip
+
+home.pdfToCbz.title=PDF to CBZ
+home.pdfToCbz.desc=Convert PDF files to CBZ comic book archives.
+pdfToCbz.tags=conversion,comic,book,archive,cbz,pdf
+
 home.pdfToImage.title=PDF to Image
 home.pdfToImage.desc=Convert a PDF to a image. (PNG, JPEG, GIF, PSD)
 pdfToImage.tags=conversion,img,jpg,picture,photo,psd,photoshop
@@ -1431,6 +1439,18 @@ imageToPDF.selectText.3=Multi file logic (Only enabled if working with multiple
 imageToPDF.selectText.4=Merge into single PDF
 imageToPDF.selectText.5=Convert to separate PDFs

+#cbzToPDF
+cbzToPDF.title=CBZ to PDF
+cbzToPDF.header=CBZ to PDF
+cbzToPDF.submit=Convert to PDF
+cbzToPDF.selectText=Select CBZ file
+
+#pdfToCBZ
+pdfToCBZ.title=PDF to CBZ
+pdfToCBZ.header=PDF to CBZ
+pdfToCBZ.submit=Convert to CBZ
+pdfToCBZ.selectText=Select PDF file
+pdfToCBZ.dpi=DPI (Dots Per Inch)

 #pdfToImage
 pdfToImage.title=PDF to Image
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html th:data-language="${#locale.toString()}" th:dir="#{language.direction}" th:lang="${#locale.language}"
+  xmlns:th="https://www.thymeleaf.org">
+
+<head>
+  <th:block th:insert="~{fragments/common :: head(title=#{cbzToPDF.title}, header=#{cbzToPDF.header})}"></th:block>
+</head>
+
+<body>
+  <th:block th:insert="~{fragments/common :: game}"></th:block>
+  <div id="page-container">
+    <div id="content-wrap">
+      <th:block th:insert="~{fragments/navbar.html :: navbar}"></th:block>
+      <br><br>
+      <div class="container">
+        <div class="row justify-content-center">
+          <div class="col-md-6 bg-card">
+            <div class="tool-header">
+              <span class="material-symbols-rounded tool-header-icon convertto">auto_stories</span>
+              <span class="tool-header-text" th:text="#{cbzToPDF.header}"></span>
+            </div>
+            <form enctype="multipart/form-data" id="cbzToPDFForm" method="post"
+              th:action="@{'/api/v1/convert/cbz/pdf'}">
+              <div
+                th:replace="~{fragments/common :: fileSelector(name='fileInput', multipleInputsForSingleRequest=false, accept='.cbz,.zip', inputText=#{cbzToPDF.selectText})}">
+              </div>
+              
+              <br>
+              <button class="btn btn-primary" id="submitBtn" th:text="#{cbzToPDF.submit}" type="submit">Convert to PDF</button>
+            </form>
+          </div>
+        </div>
+      </div>
+    </div>
+    <th:block th:insert="~{fragments/footer.html :: footer}"></th:block>
+  </div>
+</body>
+
+</html>
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html th:data-language="${#locale.toString()}" th:dir="#{language.direction}" th:lang="${#locale.language}"
+  xmlns:th="https://www.thymeleaf.org">
+
+<head>
+  <th:block th:insert="~{fragments/common :: head(title=#{pdfToCBZ.title}, header=#{pdfToCBZ.header})}"></th:block>
+</head>
+
+<body>
+  <th:block th:insert="~{fragments/common :: game}"></th:block>
+  <div id="page-container">
+    <div id="content-wrap">
+      <th:block th:insert="~{fragments/navbar.html :: navbar}"></th:block>
+      <br><br>
+      <div class="container">
+        <div class="row justify-content-center">
+          <div class="col-md-6 bg-card">
+            <div class="tool-header">
+              <span class="material-symbols-rounded tool-header-icon convert">auto_stories</span>
+              <span class="tool-header-text" th:text="#{pdfToCBZ.header}"></span>
+            </div>
+            <form enctype="multipart/form-data" id="pdfToCBZForm" method="post"
+              th:action="@{'/api/v1/convert/pdf/cbz'}">
+              <div
+                th:replace="~{fragments/common :: fileSelector(name='fileInput', multipleInputsForSingleRequest=false, accept='application/pdf', inputText=#{pdfToCBZ.selectText})}">
+              </div>
+              <div class="mb-3">
+                <label for="dpi" th:text="#{pdfToCBZ.dpi}">DPI:</label>
+                <input class="form-control" id="dpi" max="600" min="72" name="dpi" required step="1" type="number" value="300">
+              </div>
+              <br>
+              <button class="btn btn-primary" id="submitBtn" th:text="#{pdfToCBZ.submit}" type="submit">Convert to CBZ</button>
+            </form>
+          </div>
+        </div>
+      </div>
+    </div>
+    <th:block th:insert="~{fragments/footer.html :: footer}"></th:block>
+  </div>
+</body>
+
+</html>
@@ -47,6 +47,9 @@
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('img-to-pdf', 'picture_as_pdf', 'home.imageToPdf.title', 'home.imageToPdf.desc', 'imageToPdf.tags', 'convertto')}">
      </div>
+      <div
+        th:replace="~{fragments/navbarEntry :: navbarEntry('cbz-to-pdf', 'auto_stories', 'home.cbzToPdf.title', 'home.cbzToPdf.desc', 'cbzToPdf.tags', 'convertto')}">
+      </div>
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('file-to-pdf', 'draft', 'home.fileToPDF.title', 'home.fileToPDF.desc', 'fileToPDF.tags', 'convertto')}">
      </div>
@@ -71,6 +74,9 @@
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('pdf-to-img', 'photo_library', 'home.pdfToImage.title', 'home.pdfToImage.desc', 'pdfToImage.tags', 'convert')}">
      </div>
+      <div
+        th:replace="~{fragments/navbarEntry :: navbarEntry('pdf-to-cbz', 'auto_stories', 'home.pdfToCbz.title', 'home.pdfToCbz.desc', 'pdfToCbz.tags', 'convert')}">
+      </div>
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('pdf-to-pdfa', 'picture_as_pdf', 'home.pdfToPDFA.title', 'home.pdfToPDFA.desc', 'pdfToPDFA.tags', 'convert')}">
      </div>
@@ -98,13 +104,16 @@

    </div>
  </div>
-  <div id="convertGroup" class="feature-group">
+  <div class="feature-group" id="convertGroup">
    <div th:replace="~{fragments/featureGroupHeader :: featureGroupHeader(groupTitle=#{navbar.sections.convertTo})}">
    </div>
    <div class="nav-group-container">
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('img-to-pdf', 'picture_as_pdf', 'home.imageToPdf.title', 'home.imageToPdf.desc', 'imageToPdf.tags', 'convertto')}">
      </div>
+      <div
+        th:replace="~{fragments/navbarEntry :: navbarEntry('cbz-to-pdf', 'auto_stories', 'home.cbzToPdf.title', 'home.cbzToPdf.desc', 'cbzToPdf.tags', 'convertto')}">
+      </div>
      <div
        th:replace="~{fragments/navbarEntry :: navbarEntry('file-to-pdf', 'draft', 'home.fileToPDF.title', 'home.fileToPDF.desc', 'fileToPDF.tags', 'convertto')}">
      </div>
@@ -0,0 +1,84 @@
+package stirling.software.SPDF.controller.api.converters;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.mock.web.MockMultipartFile;
+
+import stirling.software.common.util.CbzUtils;
+
+class CbzUtilsTest {
+
+    @Test
+    void testIsCbzFile_ValidCbzFile() {
+        MockMultipartFile cbzFile =
+                new MockMultipartFile(
+                        "file", "test.cbz", "application/zip", "test content".getBytes());
+
+        assertTrue(CbzUtils.isCbzFile(cbzFile));
+    }
+
+    @Test
+    void testIsCbzFile_ValidZipFile() {
+        MockMultipartFile zipFile =
+                new MockMultipartFile(
+                        "file", "test.zip", "application/zip", "test content".getBytes());
+
+        assertTrue(CbzUtils.isCbzFile(zipFile));
+    }
+
+    @Test
+    void testIsCbzFile_InvalidFile() {
+        MockMultipartFile textFile =
+                new MockMultipartFile("file", "test.txt", "text/plain", "test content".getBytes());
+
+        assertFalse(CbzUtils.isCbzFile(textFile));
+    }
+
+    @Test
+    void testIsCbzFile_NoFilename() {
+        MockMultipartFile noNameFile =
+                new MockMultipartFile("file", null, "application/zip", "test content".getBytes());
+
+        assertFalse(CbzUtils.isCbzFile(noNameFile));
+    }
+
+    @Test
+    void testIsCbzFile_PdfFile() {
+        MockMultipartFile pdfFile =
+                new MockMultipartFile(
+                        "file", "document.pdf", "application/pdf", "pdf content".getBytes());
+
+        assertFalse(CbzUtils.isCbzFile(pdfFile));
+    }
+
+    @Test
+    void testIsCbzFile_JpegFile() {
+        MockMultipartFile jpegFile =
+                new MockMultipartFile("file", "image.jpg", "image/jpeg", "jpeg content".getBytes());
+
+        assertFalse(CbzUtils.isCbzFile(jpegFile));
+    }
+
+    @Test
+    void testIsCbzFile_RarFile() {
+        MockMultipartFile rarFile =
+                new MockMultipartFile(
+                        "file",
+                        "archive.rar",
+                        "application/x-rar-compressed",
+                        "rar content".getBytes());
+
+        assertFalse(CbzUtils.isCbzFile(rarFile));
+    }
+
+    @Test
+    void testIsCbzFile_MixedCaseExtension() {
+        MockMultipartFile cbzFile =
+                new MockMultipartFile(
+                        "file", "test.CBZ", "application/zip", "test content".getBytes());
+
+        assertTrue(CbzUtils.isCbzFile(cbzFile));
+    }
+}
@@ -0,0 +1,100 @@
+package stirling.software.SPDF.controller.api.converters;
+
+import java.io.IOException;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.springframework.mock.web.MockMultipartFile;
+
+import stirling.software.common.service.CustomPDFDocumentFactory;
+import stirling.software.common.util.PdfToCbzUtils;
+
+public class PdfToCbzUtilsTest {
+
+    @Mock private CustomPDFDocumentFactory pdfDocumentFactory;
+
+    @BeforeEach
+    public void setUp() {
+        MockitoAnnotations.openMocks(this);
+    }
+
+    @Test
+    public void testIsPdfFile() {
+        MockMultipartFile pdfFile =
+                new MockMultipartFile("test", "test.pdf", "application/pdf", new byte[10]);
+        MockMultipartFile nonPdfFile =
+                new MockMultipartFile("test", "test.txt", "text/plain", new byte[10]);
+        MockMultipartFile noNameFile =
+                new MockMultipartFile("test", null, "application/pdf", new byte[10]);
+
+        Assertions.assertTrue(PdfToCbzUtils.isPdfFile(pdfFile));
+        Assertions.assertFalse(PdfToCbzUtils.isPdfFile(nonPdfFile));
+        Assertions.assertFalse(PdfToCbzUtils.isPdfFile(noNameFile));
+    }
+
+    @Test
+    public void testConvertPdfToCbz_NullFile() {
+        IllegalArgumentException exception =
+                Assertions.assertThrows(
+                        IllegalArgumentException.class,
+                        () -> {
+                            PdfToCbzUtils.convertPdfToCbz(null, 300, pdfDocumentFactory);
+                        });
+        Assertions.assertEquals("File cannot be null or empty", exception.getMessage());
+    }
+
+    @Test
+    public void testConvertPdfToCbz_EmptyFile() {
+        MockMultipartFile emptyFile =
+                new MockMultipartFile("test", "test.pdf", "application/pdf", new byte[0]);
+
+        IllegalArgumentException exception =
+                Assertions.assertThrows(
+                        IllegalArgumentException.class,
+                        () -> {
+                            PdfToCbzUtils.convertPdfToCbz(emptyFile, 300, pdfDocumentFactory);
+                        });
+        Assertions.assertEquals("File cannot be null or empty", exception.getMessage());
+    }
+
+    @Test
+    public void testConvertPdfToCbz_NonPdfFile() {
+        MockMultipartFile nonPdfFile =
+                new MockMultipartFile("test", "test.txt", "text/plain", new byte[10]);
+
+        IllegalArgumentException exception =
+                Assertions.assertThrows(
+                        IllegalArgumentException.class,
+                        () -> {
+                            PdfToCbzUtils.convertPdfToCbz(nonPdfFile, 300, pdfDocumentFactory);
+                        });
+        Assertions.assertEquals("File must be a PDF", exception.getMessage());
+    }
+
+    @Test
+    public void testConvertPdfToCbz_ValidPdf() throws IOException {
+        // Create a simple mock PDF
+        MockMultipartFile pdfFile =
+                new MockMultipartFile("test", "test.pdf", "application/pdf", new byte[100]);
+
+        // Mock the PDF document
+        PDDocument mockDocument = Mockito.mock(PDDocument.class);
+        Mockito.when(mockDocument.getNumberOfPages()).thenReturn(1);
+        Mockito.when(pdfDocumentFactory.load(pdfFile)).thenReturn(mockDocument);
+
+        // structure
+        Assertions.assertThrows(
+                Exception.class,
+                () -> {
+                    PdfToCbzUtils.convertPdfToCbz(pdfFile, 300, pdfDocumentFactory);
+                });
+
+        // Verify that load was called
+        Mockito.verify(pdfDocumentFactory).load(pdfFile);
+    }
+}