多线程 ： 使用 CompletionService 多线程返回结果

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;

public class CompleteServiceTest {

	public static void main(String[] args) {

		ExecutorService threadPool = Executors.newFixedThreadPool(3);
		CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(threadPool);
		for (int i = 0; i < 3; 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 < 3; i++) {
			try {
				int result = completionService.take().get();
				System.out.println(result);
			} catch (InterruptedException | ExecutionException e) {
				e.printStackTrace();
			}

		}

	}

}