ThreadTaskCancel.java

package br.com.leonardoz.patterns.task_cancel;

/**
 * Pattern: Thread Task Cancel
 *
 * Motivations: Tasks that offers a cancel option are common in programming.
 * Background tasks, implemented by threads, are common in Java too and often
 * they need to be canceled.
 * 
 * Intent: Show how to create a cancel mechanism using threads. Inside the
 * Runnable code, we use Thread.currentThread().isInterrupted() to identify the
 * thread state and to keep it running or not.
 *
 * Applicability: When background tasks needs a cancel option.
 * 
 */
public class ThreadTaskCancel {

	private Thread thread;
	private Runnable task = () -> {
		while (!Thread.currentThread().isInterrupted()) {
			// keep going - be aware of using this Pattern with the Interrupted exception! It won't work.
		}
	};

	public void run() {
		thread = new Thread(task);
		thread.start();
	}

	public void cancel() {
		if (thread != null) {
			thread.interrupt();
		}
	}

}