Java ThreadGroup catch uncaught exceptions in a group of threads

Introduction

Java can capture all the uncaught exceptions thrown by any Thread of the ThreadGroup class.

JVM looks for the uncaught exception handler for the ThreadGroup class of the thread.

If this method doesn't exist, the JVM looks for the default uncaught exception handler.

If none of the handlers exit, the JVM writes the stack trace of the exception in the console and exits the program. 


import java.util.Random;

public class Main {

  public static void main(String[] args) {
    // Create a MyThreadGroup object
    MyThreadGroup threadGroup = new MyThreadGroup("MyThreadGroup");
    // Create a Task object
    Task task = new Task();
    // Create and start two Thread objects for this Task
    for (int i = 0; i < 2; i++) {
      Thread t = new Thread(threadGroup, task);
      t.start();//from w  w  w .  ja  va2 s  .  co m
    }
  }

}

class MyThreadGroup extends ThreadGroup {
  public MyThreadGroup(String name) {
    super(name);
  }

  @Override
  public void uncaughtException(Thread t, Throwable e) {
    // Prints the name of the Thread
    System.out.printf("The thread %s has thrown an Exception\n", t.getId());
    // Print the stack trace of the exception
    e.printStackTrace(System.out);
    // Interrupt the rest of the threads of the thread group
    System.out.printf("Terminating the rest of the Threads\n");
    interrupt();
  }
}

class Task implements Runnable {

  @Override
  public void run() {
    while (true) {
      Integer.parseInt("DEMO2s.com");
      // Check if the Thread has been interrupted
      if (Thread.currentThread().isInterrupted()) {
        System.out.printf("%d : Interrupted\n", Thread.currentThread().getId());
        return;
      }
    }
  }
}



PreviousNext

Related