使用GUI启动线程（Java）

Question

My GUI freezes whenever the run method in the thread is called, does anybody know why?

Main :

try {
        // Set System Look and Feel
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } catch (UnsupportedLookAndFeelException e) {
        // handle exception
    } catch (ClassNotFoundException e) {
        // handle exception
    } catch (InstantiationException e) {
        // handle exception
    } catch (IllegalAccessException e) {
        // handle exception
    }
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                MainFrame frame = new MainFrame(null, null);
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

run method from thread:

public void run() {
    while (true) {
        System.out.println("test");
    }
}

actionListener that is supposed to start the thread:

private ActionListener btnStartListener = new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        robot.run();
    }
};




public class RobotThread implements Runnable {
@Override
public void run() {
    while (true) {
        System.out.println("test");
    }
}

}

Answer 1

That's because the run() method does not start a new thread. Assuming your robot reference refers to an instance of Runnable you need to call the following;

new Thread(robot).start();

Calling start() will start a new thread, and call the run() method on it. Currently your run() method is being run on the same thread it is called from (in your instance the event dispatch thread).