线程池

线程池事先准备好一定数目的线程，需要使用时把线程当作载体，直接拿出来用，无需再创建。

以下代码演示如何在java中使用线程池：

package com.cxf.multithread.pool;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TestForPool {
    public static void main(String[] args) {
        ExecutorService service = Executors.newFixedThreadPool(10);
        service.execute(new Myjob());
        service.execute(new Myjob());
        service.execute(new Myjob());
        service.execute(new Myjob());
        service.shutdown();
    }
}

class Myjob implements Runnable {

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + " is running");
    }
}

输出结果：

pool-1-thread-1 is running
pool-1-thread-4 is running
pool-1-thread-2 is running
pool-1-thread-3 is running

java中通过newFixedThreadPool方法来实现线程池，创建线程池相当于创建一个服务。

用execute运行线程相当于开启服务，线程结束后需要用shutdown关闭服务。