Download & extract JDKs as separate task

build.gradle

@@ -59,6 +59,54 @@ gradle.projectsLoaded {
     if (!serverDir.exists()) serverDir.mkdirs()
 }
 
+def jdkDir = file("${buildDir}/jdks")
+def jdkVersion = "21"
+
+def downloadJdk(String jdkUrl, File destinationDir) {
+    destinationDir.mkdirs()
+    def jdkArchive = new File(destinationDir, jdkUrl.substring(jdkUrl.lastIndexOf('/') + 1))
+
+    if (!jdkArchive.exists()) {
+        println "Downloading JDK from: $jdkUrl"
+        new URL(jdkUrl).withInputStream { downloadStream ->
+            jdkArchive.withOutputStream { outputStream ->
+                outputStream << downloadStream
+            }
+        }
+        println "Downloaded: ${jdkArchive.name}"
+    }
+
+    def tempDir = new File(destinationDir, "temp")
+    if (jdkArchive.name.endsWith('.zip')) {
+        copy {
+            from zipTree(jdkArchive)
+            into tempDir
+        }
+    } else if (jdkArchive.name.endsWith('.tar.gz')) {
+        copy {
+            from tarTree(resources.gzip(jdkArchive))
+            into tempDir
+        }
+    }
+
+    def extractedDir = tempDir.listFiles()?.find { it.isDirectory() }
+    if (extractedDir) {
+        def finalDir = new File(destinationDir, "bin")
+        extractedDir.renameTo(finalDir)
+    }
+
+    delete(tempDir)
+}
+
+task downloadJdks {
+    doLast {
+        downloadJdk("https://corretto.aws/downloads/latest/amazon-corretto-${jdkVersion}-x64-linux-jdk.tar.gz", file("${jdkDir}/linux"))
+        downloadJdk("https://corretto.aws/downloads/latest/amazon-corretto-${jdkVersion}-x64-windows-jdk.zip", file("${jdkDir}/win"))
+        downloadJdk("https://corretto.aws/downloads/latest/amazon-corretto-${jdkVersion}-aarch64-macos-jdk.tar.gz", file("${jdkDir}/mac-aarch64"))
+        downloadJdk("https://corretto.aws/downloads/latest/amazon-corretto-${jdkVersion}-x64-macos-jdk.tar.gz", file("${jdkDir}/mac-x64"))
+    }
+}
+
 jlink {
     imageZip = project.file("${buildDir}/distributions/${name}-${version}.zip")
     options = ['--strip-debug', '--compress', '2', '--no-header-files', '--no-man-pages', '--ignore-signing-information']
@@ -67,19 +115,19 @@ jlink {
     }
 
     targetPlatform("linux") {
-        jdkHome = jdkDownload("https://corretto.aws/downloads/latest/amazon-corretto-21-x64-linux-jdk.tar.gz")
+        jdkHome = file("${jdkDir}/linux/bin")
     }
 
     targetPlatform("win") {
-        jdkHome = jdkDownload("https://corretto.aws/downloads/latest/amazon-corretto-21-x64-windows-jdk.zip")
+        jdkHome = file("${jdkDir}/win/bin")
     }
 
     targetPlatform("mac-aarch64") {
-        jdkHome = jdkDownload("https://corretto.aws/downloads/latest/amazon-corretto-21-aarch64-macos-jdk.tar.gz")
+        jdkHome = file("${jdkDir}/mac-aarch64/bin/Contents/Home")
     }
 
     targetPlatform("mac-x64") {
-        jdkHome = jdkDownload("https://corretto.aws/downloads/latest/amazon-corretto-21-x64-macos-jdk.tar.gz")
+        jdkHome = file("${jdkDir}/mac-x64/bin/Contents/Home")
     }
 }