Here you can find the source of runInBackground(final Runnable task)
public static void runInBackground(final Runnable task)
//package com.java2s; //License from project: Apache License import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class Main { public static void runInBackground(final Runnable task) { final ExecutorService executor = Executors.newSingleThreadExecutor(); executor.submit(task);/* w w w . j a v a 2 s.c o m*/ } }