Executors 和 ExecutorService

import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;public class TestOften{public static void main(String[] args) {ExecutorService exec = Executors.newCachedThreadPool();for(int i = 0; i<5;i++)exec.execute(new ListOff());exec.shutdown();}}class ListOff implements Runnable{protected int countDown = 10;public static int taskCount = 0;//全局的private final int id = taskCount++;//私有的，属于每个对象，只修改一次public ListOff(){}public String status(){return id+" "+(countDown > 0?countDown:"listOff");}public void run(){while(countDown-->0){System.out.println(status());Thread.yield();}}}

Executors类可以获得ExecutorServices对象，ExecutorServices接口继承了Executor,ExecutorServices里面提供了对线程的操作方法

同理，Executors.newFixedThreadPool(int nThreads)  创建固定线程数的线程池, 返回一个Executor；

 newSingleThreadExecutor()   :，返回一个Executor, 按序列化执行任务，就是按提交任务的顺序执行任务