学步园

package cn.itcast.hemai2;

import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
 * Future设计模式
 * @author admin
 *
 */
public class CallableAndFuture {
	public static void main(String[] args) {
		ExecutorService threadPool = Executors.newSingleThreadExecutor();
//		threadPool.submit(null);如果需要这个线程的请求返回数据用submit，如果不需要用exe....
		Future<String> future = threadPool.submit(new Callable<String>() {
			@Override
			public String call() throws Exception {//call方法执行实际工作内容和返回对象 
				Thread.sleep(2000);
				return "hello";
			}
		});
		
		System.out.println("等待结果 ");//在等待结果时间，此时可以处理其它的业务逻辑。
		
		try {
			System.out.println("Future模式在处理了其它的业务逻辑后得到结果 "+future.get());
			System.out.println("Future模式在处理了其它的业务逻辑后得到结果 "+future.get(3,TimeUnit.SECONDS));//超过一秒得不到结果，就抛出异常。
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (ExecutionException e) {
			e.printStackTrace();
		} catch (TimeoutException e) {
			System.out.println("TimeoutException");
			e.printStackTrace();
		}
		
		
		
		
		//批量提交任务，并且得到每个任务返回的结果，一旦获得就显示出来 。
		ExecutorService threadPool2 = Executors.newFixedThreadPool(10);
		CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(threadPool2) ;
		for (int i = 0; i < 10; i++) {
			final int seq = i;
			completionService.submit(new Callable<Integer>() {
				@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();
			}
		}
		
		
	}

}

http://www.blogjava.net/shinzey/archive/2011/09/29/359781.html

http://www.thebigdata.cn/JiShuBoKe/4914.html