线程池Executors、Callable与Future的应用

package com.mrm.test.action;

import java.util.Random;
import java.util.concurrent.*;

public class test {
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newSingleThreadExecutor();
        Future<String> future = executorService.submit(new Callable<String>() {
            @Override
            public String call() throws Exception {
                Thread.sleep(1000);
                return "hello";
            }
        });
        try {
            System.out.println("等待结果");
            System.out.println(future.get());
            executorService.shutdown();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }

        ExecutorService executorService2 = Executors.newFixedThreadPool(10);
        CompletionService<Integer> completionService =
                new ExecutorCompletionService<Integer>(executorService2);
        for (int i = 0; i < 10; i++) {
            final int seq = i;
            completionService.submit(new Callable<Integer>() {
                @Override
                public Integer call() throws Exception {
                    return seq;
                }
            });
        }

        for (int i = 0; i < 10; i++) {
            try {
                Thread.sleep(new Random().nextInt(3000));
                System.out.println(completionService.take().get());
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
        }
        executorService.shutdown();
        executorService2.shutdown();
    }

}