java 线程池问题

[love_love]

	public void execute(JobExecutionContext arg0) throws JobExecutionException {
		ExecutorService pool = Executors.newCachedThreadPool();　//1
//		ExecutorService pool = Executors.newFixedThreadPool(2);     //2
		for(int i=0 ; i<2 ;i++){
			pool.execute(new ThreadListener());
		}
		System.out.println(pool.shutdownNow().size());
	}

ThreadListener类

public class ThreadListener implements Runnable {
	


	@Override
	public void run() {
		// TODO Auto-generated method stub
		System.out.println(new Date()+" "+Thread.currentThread().getName()+" 正在运行");
		int i = 10/0;
		try {
			Thread.sleep(10000);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

请问大神两个问题:
1. 1标记的无界自动回收线程和2固定大小线程数为2 ，两者在此处应该是一样的吧。哪个对此处稍好点？
2. 在出现异常时，线程退出，是否可以被　垃圾回收机制回收。会存在内存溢出的问题吗？

[dracularking]

1.一样的，总共两个线程 2. jvm退出后就都回收了

[love_love]

出现异常，原来的线程是直接被退出？然后加入一个新的线程进来吗？

Exception in thread "pool-8-thread-2" 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
Thu Oct 29 08:18:04 CST 2015 pool-8-thread-2 正在运行
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
java.lang.ArithmeticException: / by zero
	at com.yongan.quartz.ThreadListener.run(ThreadListener.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Thu Oct 29 08:18:06 CST 2015 pool-9-thread-1 正在运行
Thu Oct 29 08:18:06 CST 2015 pool-9-thread-2 正在运行
Exception in thread "pool-9-thread-1" java.lang.ArithmeticException: / by zero
Exception in thread "pool-9-thread-2" 	at com.yongan.quartz.ThreadListener.run(ThreadListener.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
0
java.lang.ArithmeticException: / by zero
	at com.yongan.quartz.ThreadListener.run(ThreadListener.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Thu Oct 29 08:18:08 CST 2015 pool-10-thread-1 正在运行
Exception in thread "pool-10-thread-1" java.lang.ArithmeticException: / by zero
	at com.yongan.quartz.ThreadListener.run(ThreadListener.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Thu Oct 29 08:18:08 CST 2015 pool-10-thread-2 正在运行

我打印出来的线程池名，都是在增加。我担心原来的没退出，还在线程池中？

[执笔记忆的空白]

你线程并没有退出啊 stop方法

[love_love]

线程不是异常了 10/0 然后这线程就算执行为了，异常退出吧。

[dracularking]

引用 4 楼 woxinfeixian93 的回复:

线程不是异常了 10/0 然后这线程就算执行为了，异常退出吧。

为了验证这个问题，异常发生后可以查看线程池中还有多少线程的