How to keep a method running continuously in background until the program ends?

Question

I want to know, how to keep a method running in the background. ie. this method starts when the program starts and keeps executing its statements until the program is closed

Answer 1

"SWING isn't thread safe" as you may have seen in may of the Java Docs.

Best way is to use a SwingWorker class. It provides functionality for calculation of results or performance of tasks that have long execution times.

Answer 2

In the simplest way, you could have something like this:

import javax.swing.JFrame;

public class TestBackgroudMethod {

    public static void main(final String[] args) {

        MyBackgroudMethod thread = new MyBackgroudMethod();
        thread.setDaemon(true);
        thread.start();

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame jFrame = new JFrame();
                jFrame.setSize(200, 200);
                jFrame.setVisible(true);
            }
        });
    }

    public static class MyBackgroudMethod extends Thread {

        @Override
        public void run() {
            while (true) {
                System.out.println("Executed!");
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

    }

}

Edit

---

Added sample with swing worker:

import javax.swing.JFrame;
import javax.swing.SwingWorker;

public class TestBackgroudMethod {

    public static void main(final String[] args) {

        new SwingBackgroupWorker().execute();

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame jFrame = new JFrame();
                jFrame.setSize(200, 200);
                jFrame.setVisible(true);
            }
        });
    }

    public static class SwingBackgroupWorker extends SwingWorker<Object, Object> {

        @Override
        protected Object doInBackground() throws Exception {
            while (true) {
                java.awt.EventQueue.invokeLater(new Runnable() {
                    public void run() {
                        System.out.println("executed");
                        // here the swing update
                    }
                });
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

    }

}