Very simple utility class for running stuff on an executor. Depends on Google Guava (written with 'com.google.guava:guava:23.3-android')

Background.java

package foo.bar.baz;

import android.support.annotation.CheckResult;
import android.support.annotation.NonNull;

import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;

import java.util.concurrent.Callable;
import java.util.concurrent.Executors;

/**
 * Utility class for running stuff in the background.
 * Allows for fire-and-forget task running with optional listeners.
 */
public class Background {
    private static final ListeningExecutorService mBackgroundExecutor;
    static {
        mBackgroundExecutor = MoreExecutors.listeningDecorator(Executors.newCachedThreadPool());
    }

    private Background() { /* Instantiation is not allowed. */ }

    public static ListenableFuture run(@NonNull Runnable runnable) {
        return mBackgroundExecutor.submit(runnable);
    }

    public static <V> ListenableFuture<V> run(@NonNull Callable<V> callable) {
        return mBackgroundExecutor.submit(callable);
    }

    public static ListenableFuture run(@NonNull Runnable runnable, @NonNull Runnable listener) {
        final ListenableFuture future = run(runnable);
        future.addListener(listener, mBackgroundExecutor);
        return future;
    }

    @CheckResult
    public static <V> ListenableFuture<V> run(@NonNull Callable<V> callable, @NonNull Runnable listener) {
        final ListenableFuture<V> future = run(callable);
        future.addListener(listener, mBackgroundExecutor);
        return future;
    }

    public static void addListener(@NonNull ListenableFuture future, @NonNull Runnable listener) {
        future.addListener(listener, mBackgroundExecutor);
    }
}