public class CallableAndFuture {	/**	 * @param args	 */	public static void main(String[] args) {		ExecutorService threadPool =  Executors.newSingleThreadExecutor();		Future
    
      future =			threadPool.submit(				new Callable
     
      () {					public String call() throws Exception {						Thread.sleep(2000);						return "hello";					};				}		);		System.out.println("等待结果");		try {			System.out.println("拿到结果：" + future.get());		} catch (InterruptedException e) {			// TODO Auto-generated catch block			e.printStackTrace();		} catch (Exception e) {			// TODO Auto-generated catch block			e.printStackTrace();		}				ExecutorService threadPool2 =  Executors.newFixedThreadPool(10);		CompletionService
      
        completionService = new ExecutorCompletionService
       
        (threadPool2);		for(int i=1;i<=10;i++){			final int seq = i;			completionService.submit(new Callable
        
         () {				@Override				public Integer call() throws Exception {					Thread.sleep(new Random().nextInt(5000));					return seq;				}			});		}		for(int i=0;i<10;i++){			try {				System.out.println(						completionService.take().get());			} catch (InterruptedException e) {				// TODO Auto-generated catch block				e.printStackTrace();			} catch (ExecutionException e) {				// TODO Auto-generated catch block				e.printStackTrace();			}		}	}	}