什么是java线程池框架

多线程是程序员面试时常常会面对的问题，对多线程概念的掌握和理解水平，也常常被用来衡量一个人的编程实力。不错，普通的.多线程已经不容易了。

一、线程池结构图

二、示例

定义线程接口

6public class MyThread extends Thread {@Overridepublicvoid run() {tln(entThread()ame() + "正在执行");}}

1：newSingleThreadExecutor

10ExecutorService pool = Executors. newSingleThreadExecutor();Thread t1 = new MyThread();Thread t2 = new MyThread();Thread t3 = new MyThread();//将线程放入池中进行执行ute(t1);ute(t2);ute(t3);//关闭线程池down();

输入结果：

3pool-1-thread-1正在执行pool-1-thread-1正在执行pool-1-thread-1正在执行

2：newFixedThreadPool

13ExecutorService pool = ixedThreadPool(3);Thread t1 = new MyThread();Thread t2 = new MyThread();Thread t3 = new MyThread();Thread t4 = new MyThread();Thread t5 = new MyThread();//将线程放入池中进行执行ute(t1);ute(t2);ute(t3);ute(t4);ute(t5);down();

输入结果：

4pool-1-thread-1正在执行pool-1-thread-2正在执行pool-1-thread-1正在执行pool-1-thread-2正在执行

3 :newCachedThreadPool

14ExecutorService pool = achedThreadPool();Thread t1 = new MyThread();Thread t2 = new MyThread();Thread t3 = new MyThread();Thread t4 = new MyThread();Thread t5 = new MyThread();//将线程放入池中进行执行ute(t1);ute(t2);ute(t3);ute(t4);ute(t5);//关闭线程池down();

输入结果：

5pool-1-thread-2正在执行pool-1-thread-4正在执行pool-1-thread-3正在执行pool-1-thread-1正在执行pool-1-thread-5正在执行

4 :ScheduledThreadPoolExecutor

14ScheduledExecutorService pool = cheduledThreadPool(2);duleAtFixedRate(new Runnable() {//每隔一段时间就触发异常 @Override public void run() { //throw new RuntimeException(); tln("================"); }}, 1000, 2000, ISECONDS);duleAtFixedRate(new Runnable() {//每隔一段时间打印系统时间，证明两者是互不影响的 @Override public void run() { tln("+++++++++++++++++"); }}, 1000, 2000, ISECONDS);

输入结果：

4================+++++++++++++++++++++++++++++++++++++++++++++++++++

三、线程池核心参数

corePoolSize ： 池中核心的线程数

maximumPoolSize ： 池中允许的最大线程数。

keepAliveTime ： 当线程数大于核