feat(docker): update base images to Java 25, Spring 4, Jackson 3, Gradle 9 and optimize JVM options (Project Lilliput) (#5725)

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

build.gradle

@@ -2,7 +2,7 @@ plugins {
     id "java"
     id "jacoco"
     id "io.spring.dependency-management" version "1.1.7"
-    id "org.springframework.boot" version "3.5.9"
+    id "org.springframework.boot" version "4.0.3"
     id "org.springdoc.openapi-gradle-plugin" version "1.9.0"
     id "io.swagger.swaggerhub" version "1.3.2"
     id "com.diffplug.spotless" version "8.1.0"
@@ -15,20 +15,31 @@ import com.github.jk1.license.render.*
 import groovy.json.JsonOutput
 import groovy.json.JsonSlurper
 import groovy.xml.XmlSlurper
+import org.gradle.api.JavaVersion
 import org.gradle.api.tasks.testing.Test
+import org.gradle.jvm.toolchain.JavaLanguageVersion
 
 ext {
-    springBootVersion = "3.5.9"
+    springBootVersion = "4.0.3"
     pdfboxVersion = "3.0.6"
     imageioVersion = "3.13.0"
     lombokVersion = "1.18.42"
     bouncycastleVersion = "1.83"
-    springSecuritySamlVersion = "6.5.6"
+    springSecuritySamlVersion = "7.0.2"
     openSamlVersion = "4.3.2"
-    commonmarkVersion = "0.27.0"
-    googleJavaFormatVersion = "1.28.0"
-    logback = "1.5.25"
+    commonmarkVersion = "0.27.1"
+    googleJavaFormatVersion = "1.34.1"
+    logback = "1.5.28"
     junitPlatformVersion = "1.12.2"
+    modernJavaVersion = 21
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(project.findProperty('javaVersion')?.toString() ?: '25')
+    }
 }
 
 ext.isSecurityDisabled = { ->
@@ -70,7 +81,6 @@ allprojects {
     version = '2.5.3'
 
     configurations.configureEach {
-        exclude group: 'commons-logging', module: 'commons-logging'
         exclude group: "org.springframework.boot", module: "spring-boot-starter-tomcat"
     }
 }
@@ -138,8 +148,11 @@ subprojects {
     apply plugin: 'jacoco'
 
     java {
-        // 17 is lowest but we support and recommend 21
-        sourceCompatibility = JavaVersion.VERSION_17
+        sourceCompatibility = JavaVersion.VERSION_21
+        targetCompatibility = JavaVersion.VERSION_21
+        toolchain {
+            languageVersion = JavaLanguageVersion.of(25)
+        }
     }
 
     if (project.name != "stirling-pdf") {
@@ -167,12 +180,14 @@ subprojects {
     }
 
     configurations.configureEach {
-        exclude group: 'commons-logging', module: 'commons-logging'
         exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat'
         // Exclude vulnerable BouncyCastle version used in tableau
         exclude group: 'org.bouncycastle', module: 'bcpkix-jdk15on'
         exclude group: 'org.bouncycastle', module: 'bcutil-jdk15on'
         exclude group: 'org.bouncycastle', module: 'bcmail-jdk15on'
+        // google-java-format 1.34+ requires Guava 33.x (ImmutableSortedMapFauxverideShim);
+        // force it here so Spotless's FeatureClassLoader resolves the correct version.
+        resolutionStrategy.force 'com.google.guava:guava:33.4.8-jre'
     }
 
     dependencyManagement {
@@ -191,7 +206,11 @@ subprojects {
         compileOnly "org.projectlombok:lombok:$lombokVersion"
         annotationProcessor "org.projectlombok:lombok:$lombokVersion"
 
+        // Jackson 3 (Spring Boot 4 uses tools.jackson)
+        implementation 'org.springframework.boot:spring-boot-starter-jackson'
+
         testImplementation 'org.springframework.boot:spring-boot-starter-test'
+        testImplementation 'org.springframework.boot:spring-boot-starter-webmvc-test'
         testRuntimeOnly 'org.mockito:mockito-inline:5.2.0'
         testRuntimeOnly "org.junit.platform:junit-platform-launcher"
 
@@ -201,13 +220,15 @@ subprojects {
 
     tasks.withType(JavaCompile).configureEach {
         options.encoding = "UTF-8"
+        options.release = rootProject.ext.modernJavaVersion
         if (!project.hasProperty("noSpotless")) {
             dependsOn "spotlessApply"
         }
     }
 
     tasks.named("compileJava", JavaCompile).configure {
-        options.compilerArgs.add("-parameters")
+        // options.compilerArgs.add("-Xlint:deprecation")
+        // options.compilerArgs.add("-Xlint:unchecked")
     }
 
     def jacocoReport = tasks.named("jacocoTestReport")
@@ -387,6 +408,17 @@ subprojects {
             finalizedBy("copySwaggerDoc")
             doNotTrackState("OpenAPI plugin writes outside build directory")
         }
+
+        tasks.named("bootRun") {
+            jvmArgs = [
+                "-XX:+UseG1GC",
+                "-XX:MaxGCPauseMillis=200",
+                "-XX:G1HeapRegionSize=4m",
+                "-XX:+ExplicitGCInvokesConcurrent",
+                "-XX:+UseStringDeduplication",
+                "-XX:+UseCompactObjectHeaders"
+            ]
+        }
     }
 }
 
@@ -533,9 +565,12 @@ tasks.register('compileRestartHelper', JavaCompile) {
 
     source = fileTree(dir: 'scripts', include: 'RestartHelper.java')
     classpath = files()
-    destinationDirectory = file("${buildDir}/restart-helper-classes")
-    sourceCompatibility = JavaVersion.VERSION_17
-    targetCompatibility = JavaVersion.VERSION_17
+    destinationDirectory = layout.buildDirectory.dir("restart-helper-classes")
+    def restartMajorVersion = project.ext.modernJavaVersion
+    def restartCompatibility = JavaVersion.toVersion(restartMajorVersion.toString())
+    sourceCompatibility = restartCompatibility
+    targetCompatibility = restartCompatibility
+    options.release.set(restartMajorVersion)
 }
 
 // Task to create restart-helper.jar
@@ -544,9 +579,9 @@ tasks.register('buildRestartHelper', Jar) {
     description = 'Builds the restart-helper.jar'
     dependsOn 'compileRestartHelper'
 
-    from "${buildDir}/restart-helper-classes"
+    from layout.buildDirectory.dir("restart-helper-classes")
     archiveFileName = 'restart-helper.jar'
-    destinationDirectory = file("${buildDir}/libs")
+    destinationDirectory = layout.buildDirectory.dir("libs")
 
     manifest {
         attributes 'Main-Class': 'RestartHelper'