有返回值的多线程

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.*;

public class ServalMethod {
    /**
     * 有返回值的线程
     */
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        System.out.println("------程序开始运行------");

        Date date = new Date();

        int taskSize = 5;

        //创建一个线程池
        ExecutorService pool = Executors.newFixedThreadPool(taskSize);
        //创建多个有返回值的任务
        List<Future> futures = new ArrayList<Future>();
        for(int i=0;i<taskSize;i++){
            Callable c = new MyCallable(i+"");
            //执行线程并获取Future对象
            Future f = pool.submit(c);
//            System.out.println(">>>"+f.get().toString());
            futures.add(f);
        }
        //关闭线程池
        pool.shutdown();

        //获取所有并发任务的运行结果
        for(Future f:futures){
            //从Future对象上获取任务的返回值，并输出到控制台
            System.out.println(">>>"+f.get().toString());
        }

        Date date1 = new Date();
        System.out.println("-----程序运行结束------，程序运行时间【"+(date1.getTime()-date.getTime())+"毫秒】");
    }
}

class MyCallable implements Callable<Object>{
    private String taskNum;

    MyCallable(String taskNum){
        this.taskNum=taskNum;
    }

    @Override
    public Object call() throws Exception {
        System.out.println(">>>"+taskNum+"任务启动");
        Date dateTmpl = new Date();
        Thread.sleep(1000);
        Date dateTmp2 = new Date();
        long time = dateTmp2.getTime()-dateTmpl.getTime();
        System.out.println(">>>"+taskNum+"任务终止");
        return taskNum+"任务返回运行结果【"+time+"ms】";
    }
}

运行结果如下：