Executing main class while thread sleeps - java

Question

Can someone help me understand how threads function in java.

I have a main class:

public static void main(String[] args) {
    Runnable r = new TestThread();
    new Thread(r).start();
    executor.execute(r);
    System.out.println("Hey the thread has ended")
}

and a thread class:

public class TestThread implements Runnable {
    public class TestThread() {
        sleep(20000);
    }

    @Override
    public void run() {
    // TODO Auto-generated method stub
    }

}

How can I get the phrase:"Hey the thread has ended" without having to wait while the thread sleeps?

He asked to get the phrase without having to wait the sleep to finish so I presume that he can't remove the sleep, but he can stop the thread from working. :) — ranu, Mar 08 '16 at 17:16
There is no thread sleeping except the main thread calling the constructor. — laune, Mar 08 '16 at 17:17

ΦXocę 웃 Пepeúpa ツ · Accepted Answer · 2016-03-08T17:27:24.120

1

You can do: call the start method of the thread class, and in the Run implementation make the thread sleep...

notice that your app is going to terminate before the Thread returns from the sleep and continues

The Runnable class

    public class TestThread implements Runnable {

    @Override
    public void run() {
        // TODO Auto-generated method stub
        try {
            Thread.sleep(20000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void setParameter(String string) {
        // TODO Auto-generated method stub

    }
}

The implementation

 public static void main(String[] args) {
    TestThread r = new TestThread();
    r.setParameter("myParameterHere");
    Thread t = new Thread(r);
    t.setName("asdas");
    t.start();
    System.out.println("Hey the thread has ended");
}

edited Mar 08 '16 at 17:27

answered Mar 08 '16 at 17:18

ΦXocę 웃 Пepeúpa ツ

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"come back to continue" - you might want to reword this phrase. – laune Mar 08 '16 at 17:19
Thank you for your answer. how can I implement this if I wanna pass an argument into the run method? – MultiTask70 Mar 08 '16 at 17:25
add a method to your class and call it – ΦXocę 웃 Пepeúpa ツ Mar 08 '16 at 17:27
You mean a setter? Thank you – MultiTask70 Mar 08 '16 at 17:28

score 0 · Answer 2 · answered Mar 08 '16 at 17:28

Here it is in what is arguably it's most simple form.

public class TestThread implements Runnable {

    @Override
    public void run() {
        try {
            Thread.sleep(20000);
        } catch (InterruptedException ex) {
        }

    }

}

public void test() throws InterruptedException {
    Runnable r = new TestThread();
    Thread t = new Thread(r);
    t.start();
    // No it hasn't!
    //System.out.println("Hey the thread has ended");
    t.join();
    // It has now!
    System.out.println("Hey the thread has ended");
}

Executing main class while thread sleeps - java

2 Answers2

The Runnable class

The implementation