Copy Apk

build.gradle

//see: https://github.com/android/gradle-recipes/blob/master/Groovy/workerEnabledTransformation/app/build.gradle

import com.android.build.api.artifact.ArtifactTransformationRequest
import com.android.build.api.artifact.SingleArtifact
import com.android.build.api.variant.BuiltArtifact
import com.android.build.api.variant.BuiltArtifacts
import com.android.build.api.variant.BuiltArtifactsLoader

import javax.inject.Inject
import java.nio.file.Files

interface WorkItemParameters extends WorkParameters {
    RegularFileProperty getInputApkFile()
    RegularFileProperty getOutputApkFile()
}

abstract class WorkItem implements WorkAction<WorkItemParameters> {

    WorkItemParameters workItemParameters

    @Inject
    WorkItem(WorkItemParameters parameters) {
        this.workItemParameters = parameters
    }

    void execute() {
        workItemParameters.getOutputApkFile().get().getAsFile().delete()
        Files.copy(
            workItemParameters.getInputApkFile().getAsFile().get().toPath(),
            workItemParameters.getOutputApkFile().get().getAsFile().toPath())
    }
}

abstract class CopyApksTask extends DefaultTask {

    @Internal
    WorkerExecutor workers

    @Inject
    CopyApksTask(WorkerExecutor workerExecutor) {
        this.workers = workerExecutor
    }

    @InputFiles
    abstract DirectoryProperty getApkFolder()

    @OutputDirectory
    abstract DirectoryProperty getOutFolder()

    @Internal
    abstract Property<ArtifactTransformationRequest<CopyApksTask>> getTransformationRequest()

    @TaskAction
    void taskAction() {
        transformationRequest.get().submit(this, workers.noIsolation(), WorkItem, { BuiltArtifact builtArtifact, Directory outputLocation, WorkItemParameters param ->
                File inputFile = new File(builtArtifact.outputFile)
                param.getInputApkFile().set(inputFile)
                param.getOutputApkFile().set(new File(outputLocation.asFile, inputFile.name))
                param.getOutputApkFile().get().getAsFile()
        })
    }
}

androidComponents {
    onVariants(selector().all(), { variant ->
        TaskProvider copyApksProvider = tasks.register('copy' + variant.getName() + 'Apks', CopyApksTask)

        ArtifactTransformationRequest request =
            variant.artifacts.use(copyApksProvider)
                .wiredWithDirectories(
                    { it.getApkFolder() },
                    { it.getOutFolder()})
                .toTransformMany(SingleArtifact.APK.INSTANCE)

        copyApksProvider.configure {
            it.transformationRequest.set(request)
            it.outFolder.set(project.layout.buildDirectory.dir("my-custom-output-directory"))
        }
    })
}