Java - InterruptedException

The Java InterruptedException is thrown when a thread is waiting, sleeping, or doing some processing, and it is interrupted. The InterruptedException is a checked exception that is thrown when a thread is waiting, sleeping, or doing some processing, and it is interrupted.

Following is the reason when JVM throws an InterruptedException in Java:

• When a thread is doing some processing, and it is interrupted, JVM throws an InterruptedException.

Constructors of InterruptedException

There are two constructors of InterruptedException class:

• InterruptedException(): This constructor is used to create an InterruptedException object without any message.
• InterruptedException(String message): This constructor is used to create an InterruptedException object with a message.

Methods of InterruptedException

There are some methods of InterruptedException class:

Example of InterruptedException

In this example, we are creating a thread that is sleeping for 5 seconds. We are interrupting the thread while it is sleeping, so JVM will throw an InterruptedException.

public class InterruptedExceptionExample extends Thread {
   public void run() {
         Thread.sleep(5000);
   }
   public static void main(String[] args) {
      InterruptedExceptionExample t1 = new InterruptedExceptionExample();
      t1.start();
      t1.interrupt();
   }
}

Output

Following is the output of the above code:

InterruptedExceptionExample.java:3: error: unreported exception InterruptedException; must be caught or declared to be thrown
         Thread.sleep(5000);
                     ^
1 error

As you can see in the output, JVM throws an InterruptedException because we are interrupting the thread while it is sleeping.

Handling InterruptedException

In this example, we are creating a thread that is sleeping for 5 seconds. We are interrupting the thread while it is sleeping, so JVM will throw an InterruptedException. We are handling this exception using try-catch block.

public class InterruptedExceptionExample extends Thread {
   public void run() {
      try {
         Thread.sleep(5000);
      } catch (InterruptedException e) {
         System.out.println("Thread is interrupted");
      }
   }
   public static void main(String[] args) {
      InterruptedExceptionExample t1 = new InterruptedExceptionExample();
      t1.start();
      t1.interrupt();
   }
}

Output

Following is the output of the above code:

Thread is interrupted

As you can see in the output, we are handling the InterruptedException using the try-catch block.

How avoid InterruptedException in Java?

There are some ways to avoid the InterruptedException in Java:

• Use the Thread.interrupted() method to check if the current thread is interrupted or not.
• Use the Thread.currentThread().isInterrupted() method to check if the current thread is interrupted or not.
• Use the Thread.sleep() method with the TimeUnit class to avoid the InterruptedException.

Avoiding InterruptedException using Thread.interrupted() method

In this example, we are creating a thread that is sleeping for 5 seconds. We are interrupting the thread while it is sleeping. We are using the Thread.interrupted() method to check if the current thread is interrupted or not.

public class HandleInterruptedException extends Thread {
   public void run() {
      while (!Thread.interrupted()) {  // Check if thread is interrupted
         try {
            System.out.println("Thread running...");
            Thread.sleep(1000);
         } catch (InterruptedException e) {
            System.out.println("Thread interrupted! Exiting...");
            break;  // Exit the loop when interrupted
         }
      }
   }
   public static void main(String[] args) throws InterruptedException {
      HandleInterruptedException t1 = new HandleInterruptedException();
      t1.start();

      Thread.sleep(3000); // Let it run for 3 seconds
      t1.interrupt();     // Interrupt the thread
   }
}

Output

Following is the output of the above code:

Thread running...
Thread running...
Thread running...
Thread interrupted! Exiting...