What is the InterruptedException exception?

InterruptedException is a checked exception in Java that is thrown when a thread is waiting, sleeping, or otherwise occupied, and that activity is interrupted by another thread.

Main points:

• It inherits from Exception.
• It indicates that a thread that was blocked (for example, in wait(), sleep(), join(), or blocking I/O operations) has received an interrupt request.
• When this exception is thrown, the thread clears the interrupt flag.

Example handling:

// Example of handling InterruptedException
public class InterruptedTask implements Runnable {
    @Override
    public void run() {
        try {
            // The thread performs some work that can be interrupted
            Thread.sleep(5000); // Example of a blocking operation
            System.out.println("Task completed without interruption.");
        } catch (InterruptedException e) {
            // An interruption was received
            System.out.println("Task was interrupted.");
            // You can re-set the interrupt flag so that
            // higher-level code knows about the interruption
            Thread.currentThread().interrupt();
            // Additional logic for exit or resource cleanup
        }
    }

    public static void main(String[] args) {
        Thread worker = new Thread(new InterruptedTask());
        worker.start();

        try {
            // Wait a bit, then interrupt the thread
            Thread.sleep(1000);
            worker.interrupt(); // Interrupt the thread
        } catch (InterruptedException e) {
            e.printStackTrace(); // Handling exception in main thread
        }
    }
}

Proper handling of InterruptedException is important for creating reliable multithreaded applications. Typical strategies:

1. Propagate the exception further (throw new InterruptedException();).
2. Re-set the interrupt flag (Thread.currentThread().interrupt();) and possibly terminate execution.
3. Catch the exception, perform cleanup, and terminate the thread.