使用另一个线程终止一个线程（循环）

Question

I am trying to find a way to terminate a thread which is currently looping infinite. With my experience I tried to create a second thread which would interrupt the first one which is looping infinite, but of course due to the infinite loop ... the first thread would never reach the sleep function. So now I'm back to this

public class Pulse{

private static int z = 0;

public static void main( String[] args ) throws Exception {
    try {
        final long stop=System.currentTimeMillis()+5L;
            //Creating the 2 threads
        for (int i=0; i<2; i++) {
            final String id=""+i+": ";
            new Thread(new Runnable() {
                public void run() {
                    System.err.println("Started thread "+id);
                    try{
                        while ( System.currentTimeMillis() < stop ) {
                                    //Purposely looping infinite
                            while(true){
                                z++;
                                System.out.println(z);
                            }
                        }
                    } catch (Exception e) {
                        System.err.println(e);
                    }
                }
            }).start();
        }
    } catch (Exception x) {
        x.printStackTrace();
    }
}
}

Answer 1

Have a volatile boolean field, say running . Make it true . Where you have while (true) change that to while (running) , and while ( System.currentTimeMillis() < stop ) { to while (running && ( System.currentTimeMillis() < stop) ) { . Now, change running to false from some other thread. That should stop the loop fairly nicely.

Answer 2

Can you change

 while(true){

to

while(!Thread.currentThread().isInterrupted()){ //or Thread.interrupted()

Now when you interrupt the thread it should correctly break out of the infinite loop.

Answer 3

You'll have to do a Thread.interrupted() call inside the loop to check if its been interrupted and handle it appropriately. Or while(!Thread.interrupted()) instead.

Answer 4

You have to do something like this:

public class ThreadStopExample {
    public static volatile boolean terminate = false;

    public static void main(String[] args) {
        new Thread(new Runnable() {
            private int i;

            public void run() {
                while (!terminate) {
                    System.out.println(i++);
                }
                System.out.println("terminated");
            }
        }).start();
        // spend some time in another thread
        for (int i = 0; i < 10000; i++) {
            System.out.println("\t" + i);
        }
        // then terminate the thread above
        terminate = true;
    }
}