Question

Why won’t this work?

I would like it to print every second.

Thanks.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class test2 {

public static void main(String[] args) {

    Timer timer = new Timer(1000, new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("hello");
        }
    });

    timer.start();
    }
}

Answer 1

Your program terminates before the timer can run even once. When the main method is terminated the program terminates and all threads will also terminate. This includes your timer thread.

Try the following:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class test2 {

    public static void main(String[] args) {

        Timer timer = new Timer(1000, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("hello");
            }
        });

        timer.start();
        }

        while (true) /* no operation */;
    }
}