First commit of new Gradle based version

build.gradle

@@ -0,0 +1,92 @@
+plugins {
+    id 'java'
+    id 'com.gradleup.shadow' version '9.0.0-beta12'
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+}
+
+sourceSets {
+    main {
+        java {
+            srcDirs = ['src']
+        }
+    }
+}
+
+jar {
+    manifest {
+        attributes 'Main-Class': 'dev.rsems.treesize.j.Main'
+    }
+}
+
+shadowJar {
+    archiveBaseName = 'treesize'
+    archiveClassifier = ''
+    archiveVersion = ''
+}
+
+// --- jpackage-based native image ---
+
+def jpackageOutputDir = layout.buildDirectory.dir('jpackage')
+def nativeOutputDir = layout.buildDirectory.dir('native')
+
+tasks.register('jpackageImage', Exec) {
+    dependsOn shadowJar
+    group = 'distribution'
+    description = 'Creates a self-contained native application image using jpackage'
+
+    def inputDir = shadowJar.destinationDirectory
+    def outputDir = jpackageOutputDir.get().asFile
+
+    doFirst {
+        delete outputDir
+        outputDir.mkdirs()
+    }
+
+    commandLine 'jpackage',
+        '--type', 'app-image',
+        '--name', 'treesize',
+        '--input', inputDir.get().asFile.absolutePath,
+        '--main-jar', 'treesize.jar',
+        '--main-class', 'dev.rsems.treesize.j.Main',
+        '--dest', outputDir.absolutePath,
+        '--java-options', '-Xmx512m'
+}
+
+tasks.register('nativeBinary', Copy) {
+    dependsOn jpackageImage
+    group = 'distribution'
+    description = 'Copies the self-contained native binary to build/native/treesize'
+
+    def outputDir = nativeOutputDir.get().asFile
+
+    doFirst {
+        outputDir.mkdirs()
+    }
+
+    from(jpackageOutputDir.get().asFile.absolutePath + '/treesize') {
+        include '**/*'
+    }
+    into outputDir.absolutePath + '/treesize'
+}
+
+tasks.register('dist') {
+    dependsOn shadowJar, nativeBinary
+    group = 'distribution'
+    description = 'Builds both treesize.jar and the native treesize binary'
+
+    doLast {
+        println ''
+        println '=== Build Complete ==='
+        println "Fat JAR:        ${shadowJar.archiveFile.get().asFile.absolutePath}"
+        println "Native image:   ${nativeOutputDir.get().asFile.absolutePath}/treesize/"
+        println "Native binary:  ${nativeOutputDir.get().asFile.absolutePath}/treesize/bin/treesize"
+        println ''
+        println 'Usage:'
+        println '  java -jar build/libs/treesize.jar          # Run via JAR'
+        println '  build/native/treesize/bin/treesize          # Run native binary'
+    }
+}