14. Interrupting Threads

Java Multithreading: Interrupting Threads 

What exactly are those pesky InterruptedExceptions? In this video I show you how to interrupt running threads in Java using the built-in thread interruption mechanism.

Code For This Tutorial

import java.util.Random;

public class App {

      public static void main(String[] args) throws InterruptedException {

            System.out.println("Starting.");

            Thread t1 = new Thread(new Runnable() {

                  public void run() {

                        Random ran = new Random();

                        for (int i = 0; i < 1E8; i++) {

                              /*

                                if(Thread.currentThread().isInterrupted()){

                                System.out.println("Interrupted!"); break; }

                               */

                              try {

                                    Thread.sleep(1);

                              } catch (InterruptedException e) {

                                    System.out.println("Interrupted!");

                                    break;

                              }

                              Math.sin(ran.nextDouble());

                        }

                  }

            });

            t1.start();

            Thread.sleep(500);

            t1.interrupt();

            t1.join();

            System.out.println("Finished.");

      }

}

***************************************************

import java.util.Random;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

import java.util.concurrent.TimeUnit;

public class App {

    public static void main(String[] args) throws InterruptedException {

        System.out.println("Starting.");

        ExecutorService exec = Executors.newCachedThreadPool();

        Future<?> fu = exec.submit(new Callable<Void>() {

            @Override

            public Void call() throws Exception {

                Random ran = new Random();

                for (int i = 0; i < 1E8; i++) {

                    if (Thread.currentThread().isInterrupted()) {

                        System.out.println("Interrupted!");

                        break;

                    }

                    Math.sin(ran.nextDouble());

                }

                return null;

            }

        });

        

        exec.shutdown();

        

        

        Thread.sleep(500);

        

        exec.shutdownNow();

        //fu.cancel(true);

        

        exec.awaitTermination(1, TimeUnit.DAYS);

        

        System.out.println("Finished.");

    }

}

Output:

Starting.

Interrupted!

Finished.