Thread.getUncaughtExceptionHandler() Method

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Description

The Java Thread getUncaughtExceptionHandler() method returns the handler invoked when this thread abruptly terminates due to an uncaught exception.

Declaration

Following is the declaration for java.lang.Thread.getUncaughtExceptionHandler() method

public Thread.UncaughtExceptionHandler getUncaughtExceptionHandler()

Parameters

NA

Return Value

This method does not return any value.

Exception

NA

Example: Getting UncaughtExceptionHandler for a Thread

The following example shows the usage of Java Thread getUncaughtExceptionHandler() method. In this program, we've created a thread class AdminThread by implementing Runnable interface. In run method, we're throwing a RuntimeException. In main method, we've created a new thread of AdminThread class and using setUncaughtExceptionHandler() method, we've set a uncaught exception handler which prints the exception raised. Now using getUncaughtExceptionHandler(), the exception handler is retrieved and printed.

Using start() method, we've started the thread and result is printed on the console.

package com.tutorialspoint;

public class ThreadDemo {

   public static void main(String[] args) {

      Thread t = new Thread(new AdminThread());
      t.setUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {

         public void uncaughtException(Thread t, Throwable e) {
            System.out.println(t + " throws exception: " + e);
         }
      });
      // this will call run() function
      t.start();
	  
      /* returns the handler invoked when this thread abruptly 
         terminates due to an uncaught exception. */
      Thread.UncaughtExceptionHandler handler = 
      t.getUncaughtExceptionHandler();
      System.out.println(handler);
   }
}

class AdminThread implements Runnable {

   public void run() {
      throw new RuntimeException();
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

com.tutorialspoint.ThreadDemo$1@28a418fc
Thread[#21,Thread-0,5,main] throws exception: java.lang.RuntimeException