Question

what I need to do is be able to stop all threads running from one thread class that implements runnable. This is what I mean: here is the beginning of my “thread” class:

public class HTTP extends Thread
{   
    int threadNumber;
    String host;
    int port;
    int timeLeft;
    private BufferedReader LocalBufferedReader;

    public HTTP(int threadNumber, String host, int port, int timeLeft)
    {
        this.threadNumber = threadNumber;
        this.host= host;
        this.port = port;
        this.timeLeft = (timeLeft * 1000);
    }

  public void run()
  {

This is how I am creating the multiple threads to do this:

 for (int n = 1; n <= m; n++) {
      new HTTP(n + 1, str, j, k).start();
    }

m is the number of threads to create. This can be anywhere from 50-1000. Now what I need to do is just abruptly stop all of them at once. How can I do that?

Answer 1

First store all the threads:

ArrayList<Thread> threads = new ArrayList<Thread>();
for (int n = 1; n <= m; n++) {
    Thread t = new HTTP(n + 1, str, j, k);
    threads.add(t);
    t.start();
 }

Now for stop method, just loop all the threads and call interrupt on them:

for(Thread thread : threads)
{
    thread.interrupt();
}

Make sure to check isIntruppted() in your HTTP threads. So you would do something like this:

public class InterruptTest {

    static class TThread extends Thread {
        public void run() {
            while(!isInterrupted()) {
                System.out.println("Do Work!!!");
                try {
                    sleep(1000);
                } catch (InterruptedException e) {
                    return;
                }
            }
        }
    }

    public static void main(String[] args) throws InterruptedException {
        Thread t = new TThread();
        t.start();

        Thread.sleep(4000);
        System.out.println("Sending interrupt!!");
        t.interrupt();
        Thread.sleep(4000);
    }

}