How to randomly set a JFrame with a simple message

Question

So I've checked out the other post which didn't help on here, I'm trying to get my frame with it's message to randomly appear on an area on the screen but when I run it, it says x and y cannot be resolved to a variable, here's the code:

    public class MyFrame extends JFrame{
       MyFrame(int width, int height, int x, int y){
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setTitle("R and Ts Main Frame");
       setSize(width, height);

       Random random = new Random();
       x = random.nextInt();
       y = random.nextInt();
       setLocation(x, y);

       JLabel label = new JLabel("Random Message");
       label.setFont(new Font("Impact", Font.BOLD|Font.PLAIN, height/3));
       label.setForeground(Color.BLUE);
       getContentPane().add(label);
}

}

and this is my main:

 public class OurMain {

  public static void main(String[] args) {
    Dimension sSize = Toolkit.getDefaultToolkit().getScreenSize();
    int w = sSize.width;
    JFrame f = new MyFrame(w/3, 100, x, y); //my errors are underlined here under the x and y
    f.setVisible(true);
}

}

Answer 1

This will solve your problem. You did not declare/create x and y before using them, but you don't need them, so just use them locally.

public class OurMain {
    public static void main(String[] args) {
        Dimension sSize = Toolkit.getDefaultToolkit().getScreenSize();
        int w = sSize.width;

        Random random = new Random();
        int x = random.nextInt(sSize.width);
        int y = random.nextInt(sSize.height);

        JFrame f = new MyFrame(w/3, 100, x, y);
    }
}

public class MyFrame extends JFrame {

    private static final long serialVersionUID = 1L;

    public MyFrame(int width, int height, int x, int y) {
        super();

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("R and Ts Main Frame");
        setSize(width, height);

        setLocation(x, y);

        JLabel label = new JLabel("Random Message");
        label.setFont(new Font("Impact", Font.BOLD | Font.PLAIN, height / 3));
        label.setForeground(Color.BLUE);

        getContentPane().add(label);
        setVisible(true);
    }
}

Result (it is loaded in a different location each time):

Answer 2

You should just add some attributes and replace some things:

MyFrame:

public class MyFrame extends JFrame {

    int x;
    int y;

    MyFrame(int width, int height, int x, int y) {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("R and Ts Main Frame");
        setSize(width, height);
        this.x = x;
        this.y = y;
        setLocation(x, y);

        JLabel label = new JLabel("Random Message");
        label.setFont(new Font("Impact", Font.BOLD | Font.PLAIN, height / 3));
        label.setForeground(Color.BLUE);
        getContentPane().add(label);
    }
}

OurMain:

public class OurMain {

    public static void main(String[] args) {
        Dimension sSize = Toolkit.getDefaultToolkit().getScreenSize();
        int w = sSize.width;
        Random random = new Random();
        int x = random.nextInt();
        int y = random.nextInt();
        JFrame f = new MyFrame(w / 3, 100, x, y); //my errors are underlined here under the x and y
        f.setVisible(true);
    }
}

EDIT:
However, random.nextInt(); is not a good idea, because your screen width&heigth has a little less then 2^32 pixels... so I would limit it to e.g.:

 public static void main(String[] args) {
       Dimension sSize = Toolkit.getDefaultToolkit().getScreenSize();
       int w = sSize.width;
       int h = sSize.height;
       int x = (int)((Math.random()* w) - w/3);
       int y = (int)((Math.random()* h) - 100);
       System.out.println(x + " " + y);
       JFrame f = new MyFrame(w / 3, 100, x, y); 
       f.setVisible(true);
 }

EDIT of EDIT:

public class OurMain {

    public static void main(String[] args) {
        Dimension sSize = Toolkit.getDefaultToolkit().getScreenSize();
        int w = sSize.width;
        int h = sSize.height;

        Random rand1 = new Random();

        int randomWidth = rand1.nextInt(w);
        int randomHeight = rand1.nextInt(h);

        Random rand2 = new Random(); // I would still use rand1

        int randomX = rand2.nextInt(w - randomWidth + 1);
        int randomY = rand2.nextInt(h - randomHeight + 1);

        JFrame f = new MyFrame(randomWidth, randomHeight, randomX, randomY);
        f.setVisible(true);
    }
}