1.Callable和Future適用於帶有返回結果的多執行緒

示例

public class CallAndFutureStudy {

	public static void main(String[] args) {
		
		ExecutorService threadPool = Executors.newSingleThreadExecutor();
		
		Future<String> result = threadPool.submit(new Callable<String>(
				) {
					@Override
					public String call() throws Exception {
						Thread.sleep(2000);
						return "hello";
					}
		});
		System.out.println("等待輸出結果");
		try {
			System.out.println("取出返回結果:"+result.get());
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ExecutionException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}
 

2.CompletionService(提交一組Callable)

處理多個帶有返回結果的執行緒

public class CallAndFutureStudy {

	public static void main(String[] args) {
		
		ExecutorService threadPool = Executors.newFixedThreadPool(10);
		CompletionService<String> completionService = new ExecutorCompletionService<String>(threadPool);
		for(int i = 0;i < 10;i++){
			final int seq = i;
			completionService.submit(new Callable<String>() {
				@Override
				public String call() throws Exception {
					Thread.sleep(new Random().nextInt(2000));
					return "ThreadName"+Thread.currentThread().getName()+"執行,返回結果:"+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();
			}
		}
	}
}
 

執行結果: