java 捕获线程里抛出的异常

import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.ThreadFactory;class ExceptionThread2 implements Runnable {@Overridepublic void run() {Thread t =Thread.currentThread();System.out.println("run by" + t);System.out.println("eh = " + t.getUncaughtExceptionHandler());throw new RuntimeException();}}class MyUncaughtExeceptionHandler implements Thread.UncaughtExceptionHandler{@Overridepublic void uncaughtException(Thread arg0, Throwable e) {System.out.println("caught " +e);}}//class HandlerThreadFactory implements ThreadFactory{////@Override//public Thread newThread(Runnable r) {//System.out.println(this +"creating new Thread");//Thread t =new Thread(r);//System.out.println("created " + t);//t.setUncaughtExceptionHandler(new MyUncaughtExeceptionHandler());//System.out.println("eh =" + t.getUncaughtExceptionHandler());//return t;//}////}public class CaptureUncaughtException{public static void main(String[] args){ExecutorService exec= Executors.newCachedThreadPool();Thread t =new Thread(new ExceptionThread2());System.out.println("created " + t);t.setUncaughtExceptionHandler(new MyUncaughtExeceptionHandler());System.out.println("eh =" + t.getUncaughtExceptionHandler());exec.execute(t);}}

上面这段代码为什么捕获不了，裘高手解答。

 

另外一种方法通过ThreadGroup 捕获

  public   class   ApplicationLoader   extends   ThreadGroup     {             private   ApplicationLoader()             {                         super("ApplicationLoader");                 }                 public   static   void   main(String[]   args)             {                         Runnable   appStarter   =   new   Runnable()                     {                                 public   void   run()                             {                                     //invoke   your   application   (i.e.MySystem.main(args)                                         throw   new   NullPointerException();   //example,   throw   a   runtime   exception                             }                     };                         new   Thread(new   ApplicationLoader(),   appStarter).start();             }                 //We   overload   this   method   from   our   parent             //ThreadGroup   ,   which   will   make   sure   that   it             //gets   called   when   it   needs   to   be.     This   is               //where   the   magic   occurs.             public   void   uncaughtException(Thread   thread,   Throwable   exception)             {                     //Handle   the   error/exception.                     //Typical   operations   might   be   displaying   a                     //useful   dialog,   writing   to   an   event   log,   etc.                         exception.printStackTrace();//example,   print   stack   trace             }     }