Separate 'UnpackAar' action

buildSrc/src/main/kotlin/UnpackAar.kt

@@ -0,0 +1,31 @@
+import org.gradle.api.artifacts.transform.InputArtifact
+import org.gradle.api.artifacts.transform.TransformAction
+import org.gradle.api.artifacts.transform.TransformOutputs
+import org.gradle.api.artifacts.transform.TransformParameters
+import org.gradle.api.file.FileSystemLocation
+import org.gradle.api.provider.Provider
+import java.io.File
+import java.nio.file.Files
+import java.util.zip.ZipEntry
+import java.util.zip.ZipFile
+
+@Suppress("UnstableApiUsage")
+abstract class UnpackAar : TransformAction<TransformParameters.None> {
+    @get:InputArtifact
+    abstract val inputArtifact: Provider<FileSystemLocation>
+
+    override fun transform(outputs: TransformOutputs) {
+        ZipFile(inputArtifact.get().asFile).use { zip ->
+            zip.entries().asSequence()
+                .filter { !it.isDirectory }
+                .filter { it.name.endsWith(".jar") }
+                .forEach { zip.unzip(it, outputs.file(it.name)) }
+        }
+    }
+}
+
+private fun ZipFile.unzip(entry: ZipEntry, output: File) {
+    getInputStream(entry).use {
+        Files.copy(it, output.toPath())
+    }
+}

integration/kotlinx-coroutines-play-services/build.gradle

@@ -2,12 +2,6 @@
  * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
-import org.gradle.api.artifacts.transform.*
-
-import java.nio.file.Files
-import java.util.zip.ZipEntry
-import java.util.zip.ZipFile
-
 ext.tasks_version = '16.0.1'
 
 def artifactType = Attribute.of("artifactType", String)
@@ -49,31 +43,3 @@ tasks.withType(dokka.getClass()) {
         packageListUrl = projectDir.toPath().resolve("package.list").toUri().toURL()
     }
 }
-
-abstract class UnpackAar implements TransformAction<TransformParameters.None> {
-    @InputArtifact
-    abstract Provider<FileSystemLocation> getInputArtifact()
-
-    @Override
-    void transform(TransformOutputs outputs) {
-        ZipFile zip = new ZipFile(inputArtifact.get().asFile)
-        try {
-            for (entry in zip.entries()) {
-                if (!entry.isDirectory() && entry.name.endsWith(".jar")) {
-                    unzipEntryTo(zip, entry, outputs.file(entry.name))
-                }
-            }
-        } finally {
-            zip.close()
-        }
-    }
-
-    private static void unzipEntryTo(ZipFile zip, ZipEntry entry, File output) {
-        InputStream stream = zip.getInputStream(entry)
-        try {
-            Files.copy(stream, output.toPath())
-        } finally {
-            stream.close()
-        }
-    }
-}