Executor来代替上篇文章中显示地创建Thread对象。它在客户端和任务执行之间提供了一个间接层，与客户端直接执行任务不同，这个中介对象将执行任务。

/** * Created by Administrator on 2017/8/31. */public class LiftOff implements Runnable {    protected int countDown = 10;    private static int taskCount = 0;    private final int id = taskCount++;    public LiftOff() {    }    public LiftOff(int countDown) {        this.countDown = countDown;    }    public String status() {        return "#" + id + "(" +                (countDown > 0 ? countDown : "LiftOff!") + ")";    }    @Override    public void run() {        while (countDown-- > 0) {            System.out.print(status());            Thread.yield();        }    }}

import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;/** * Created by Administrator on 2017/8/31. */public class MainThread {    public static void main(String[] args) {        ExecutorService exec = Executors.newCachedThreadPool();        for (int i = 0; i < 5; i++) {            exec.execute(new LiftOff());        }        exec.shutdown();        System.out.print("等待发射\r\n");    }}

输出结果：

exec.shutdown()可以防止新任务被提交给这个Executor