多线程核心7：处理未捕获的异常

使用UncaughtExceptionHandler的原因

• 主线程可以轻松发现异常，子线程不能
• 子线程的异常无法用传统方式捕获
• 在捕获到异常时也能进行处理，提高健壮性

全局异常处理使用方式

1. 实现Thread.UncaughtExceptionHandler接口

   public class MyUncaughtExceptionHandler implements Thread.UncaughtExceptionHandler {
         
         
       private String name;
   
       public MyUncaughtExceptionHandler(String name) {
         
         
           this.name = name;
       }
   
       @Override
       public void uncaughtException(Thread t, Throwable e) {
         
         
           Logger logger = Logger.getAnonymousLogger();
           logger.log(Level.WARNING, "线程异常，终止啦" + t.getName());
           System.out.println(name + "捕获了异常" + t.getName() + "异常");
       }
   }
   
   

2. 在可能出现异常的程序中使用

   public class UseOwnUncaughtExceptionHandler implements Runnable {
         
         
       public static void main(String[] args) throws InterruptedException {
         
         
           MyUncaughtExceptionHandler handler = new MyUncaughtExceptionHandler("捕获器1");
           Thread.setDefaultUncaughtExceptionHandler(handler);
   
           new Thread(new UseOwnUncaughtExceptionHandler(), "MyThread-1").start();
           Thread.sleep(300);
           new Thread(new UseOwnUncaughtExceptionHandler(), "MyThread-2").start();
           Thread.sleep(300);
           new Thread(new UseOwnUncaughtExceptionHandler(), "MyThread-3").start();
           Thread.sleep(300);
           new Thread(new UseOwnUncaughtExceptionHandler(), "MyThread-4").start();
       }
   
       @Override
       public void run() {
         
         
           throw new RuntimeException();
       }
   }
   ---------------------------------------------------------------
   一月 06, 2021 8:26:40 下午 threadcoreknowledge.uncaughtexception.MyUncaughtExceptionHandler uncaughtException
   警告: 线程异常，终止啦MyThread-1
   捕获器1捕获了异常MyThread-1异常
   一月 06, 2021 8:26:41 下午 threadcoreknowledge.uncaughtexception.MyUncaughtExceptionHandler uncaughtException
   警告: 线程异常，终止啦MyThread-2
   捕获器1捕获了异常MyThread-2异常
   捕获器1捕获了异常MyThread-3异常
   一月 06, 2021 8:26:41 下午 threadcoreknowledge.uncaughtexception.MyUncaughtExceptionHandler uncaughtException
   警告: 线程异常，终止啦MyThread-3
   一月 06, 2021 8:26:41 下午 threadcoreknowledge.uncaughtexception.MyUncaughtExceptionHandler uncaughtException
   警告: 线程异常，终止啦MyThread-4
   捕获器1捕获了异常MyThread-4异常