Java Java.lang.ThreadGroup.uncaughtException()用法及代碼示例

描述

這個java.lang.ThreadGroup.uncaughtException()當該線程組中的線程由於未捕獲的異常而停止，並且該線程沒有安裝特定的 Thread.UncaughtExceptionHandler 時，Java 虛擬機將調用該方法。

聲明

以下是聲明java.lang.ThreadGroup.uncaughtException()方法

public void uncaughtException(Thread t, Throwable e)

參數

• t- 這是即將退出的線程。

• e- 這是未捕獲的異常。

返回值

此方法不返回任何值。

異常

NA

示例

下麵的例子展示了 java.lang.ThreadGroup.uncaughtException() 方法的用法。

package com.tutorialspoint;

import java.lang.*;

public class ThreadGroupDemo implements Runnable {

   public static void main(String[] args) {
      ThreadGroupDemo tg = new ThreadGroupDemo();
      tg.func();
   }

   public void func() {
      try {
         // create a new ThreadGroup and a child for that ThreadGroup.
         newThreadGroup pGroup = new newThreadGroup("ParentThreadGroup");
         newThreadGroup cGroup = new newThreadGroup
         (pGroup,"ChildThreadGroup");

         // create another thread
         Thread thr2 = new Thread(pGroup, this);
         System.out.println("Starting " + thr2.getName() + "...");
         // this will call run() method
         thr2.start();

         // create third thread
         Thread thr3 = new Thread(cGroup, this);
         System.out.println("Starting " + thr3.getName() + "...");
         // this will call run() method
         thr3.start();

         try {
            Thread.sleep(500);
         } catch(InterruptedException ex) {}

         // interrupt the two threads
         thr2.interrupt();
         thr3.interrupt();

         // block until the other threads finish
         thr2.join();
         thr3.join();
      } catch(InterruptedException e) {
         System.out.println(e.toString());
      }
   }

   public void run() {
      try {
         System.out.print(Thread.currentThread().getName());
         System.out.println(" executing...");

         while(true) {
            Thread.sleep(500);
         }
      } catch(InterruptedException e) {
         Thread currThread = Thread.currentThread();
         System.out.print(currThread.getName());
         System.out.println(" interrupted:" + e.toString());

         // rethrow the exception
         throw new RuntimeException(e.getMessage());
      }
   }
}

class newThreadGroup extends ThreadGroup {
    
   newThreadGroup(String n) {
      super(n);
   }
    
   newThreadGroup(ThreadGroup parent, String n) {
      super(parent, n);
   }

   public void uncaughtException(Thread t, Throwable e) {
      System.out.println(t + " has unhandled exception:" + e);
   } 
}

讓我們編譯並運行上麵的程序，這將產生以下結果 -

Starting Thread-0...
Starting Thread-1...
Thread-0 executing...
Thread-1 executing...
Thread-0 interrupted:java.lang.InterruptedException:sleep interrupted
Thread[Thread-0,5,ParentThreadGroup] has unhandled exception:java.lang.RuntimeException:sleep interrupted
Thread-1 interrupted:java.lang.InterruptedException:sleep interrupted
Thread[Thread-1,5,ChildThreadGroup] has unhandled exception:java.lang.RuntimeException:sleep interrupted