Executor Service Usage

ExecutorService exec = Executors.newCachedThreadPool();

for(int i = 0; i < 10; i++)

{

    exec.execute(new Entrance(i));//obviously Entrance is another class which implements Runnable

}

TimeUnit.SECONDS.sleep(3); // this sleep code is very elegant!

exec.shutdown();

if(!exec.awaitTermination(250, TimeUnit.MILLISECONDS))

{

    print("Some tasks were not terminated");

}

 

Some points to explain:

1)ExecutorService.awaitTermination() waits for each task to complete, and if they all complete before the timeout value, it returns true, otherwise it returns false to indicate that not all tasks have completed.