Java: Timer (wait x seconds)

Question

I have a simple GUI that can save and get some data out of an .doc file.

When i press a save button, i have a label that says "Succes" or "Error" via label.setText();

Update: The code is meant to be ran in a FXMLDocumentController (built på SceneBuilder)

I want the label to go back to being empty ("") after 3 seconds..

I have tried:

try {
    Thread.sleep(1000);               
    } 
 catch(InterruptedException ex) {
Thread.currentThread().interrupt();

}

but is it like, that the sleep-function freezes the whole GUI so i can't interact with it while it's sleeping. How do i set up an timer that does not affect usability? :)

Answer 1

Create a TimerTask which is started after 3 seconds. This TimerTask has to execute the code which uses gui components via Platform.runLater(new Runnable())

Timer timer = new Timer();
timer.schedule(new TimerTask() {

        @Override
        public void run() {
            Platform.runLater(new Runnable() {
                @Override
                public void run() {
                    label.setText("");
                }
            });

        }
    }, 3000);

Answer 2

class runnable implements Runnable {
    private Object obj;
    public runnable(Object obj)
    {
        this.obj = obj;
    }
    public void run() {
        try {
            Thread.sleep(3000);
            this.obj.setText("");//right here just execute your method
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("Hello from a thread!"); //your code here
    }

}

public class Test {

    public static void main(String[] args){
        Object myObject;
        (new Thread(new runnable(myObject))).start();
    }
}

You could launch another thread to handle this. Just do your processing in the other thread. Sleep for 3 seconds then clear the lbl.

Here is an example showing how it works:

class runnable implements Runnable {
    Test test;
    public runnable(Test test)
    {
        this.test = test;
    }
    public void run() {
        try {
            Thread.sleep(3000);
            this.test.test = "test2";
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("Hello from a thread!");
    }

}

public class Test {
    public String test = "test";
    public static void main(String[] args) throws InterruptedException{
        Test test = new Test();
        System.out.println(test.test);
        (new Thread(new runnable(test))).start();
        Thread.sleep(4000);
        System.out.println(test.test);
    }
}

************************************************************UPDATE*************************************************************

class runnable implements Runnable {
    Test test;
    public runnable(Test test)
    {
        this.test = test;
    }
    public void run() {
        try {
            Thread.sleep(3000);
            this.test.label.setText("This is a test.");
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("Hello from a thread!");
    }

}

public class Test {
    public String test = "test";
    JLabel label = new JLabel("Test");
    JFrame frame = new JFrame();
    JButton button = new JButton();
    public static void main(String[] args) throws InterruptedException{
        Test test = new Test();
        test.label.setText("Test");
        test.button.setText("Test Button");
        test.button.setSize(50, 50);
        test.frame.setSize(500, 500);
        test.frame.add(test.button);
        test.frame.add(test.label);
        test.frame.setVisible(true);
        test.button.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                System.exit(0);
            }

        });
        (new Thread(new runnable(test))).start();
    }
}