Listenable callback

Async.java

public class AsyncRequest{
	ListeningExecutorService executor = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(8));
	
	public void makeRequest(String url) throws Exception{
		
		// task to execute in executor
		Callable<String> asyncTask = new Callable<String>() {

			@Override
			public String call() throws Exception {
				// Download the url
				return url;
			}
		};
		
		ListenableFuture<String> future = executor.submit(asyncTask);
		
		Futures.addCallback(future, new FutureCallback<String>() {

			@Override
			public void onSuccess(String result) {
				System.out.println(result);
			}

			@Override
			public void onFailure(Throwable t) {
				System.out.println("got some exeception.");
			}
		});		
	}
}