JFrame getLocation() always returns (0, 0)

Question

I am learning Java, and I am trying to port a silly program I made in VB.NET that bounces a green window around the screen. I think I have it all set up, except for the fact that I can't tell when the frame hits the edge of the screen (to bounce) because JFrame.getLocation() always returns (0, 0)! In addition, JFrame.setLocation(int, int) sets the location relative to the frame's current location. I'm baffled, and to new to understand why this is happening!
Here's the code, made in Eclipse IDE. The commented out section is the bouncing code that doesn't work because of my getLocation() problem. The two class files are separated by the big star line.
Right now I'm not concerned with efficiency or perfect coding, just this specific problem. However, feel free to straighten up the code (for example, I'm sure a while(true) block is not a good idea, but it works for now).
import java.awt.Toolkit;
public class Move {
     static Mover mover = new Mover();
     static int xDir = 5;
     static int yDir = 5;
     static int sleepTime = 100;
     public static void main(String[] args) {
          beginMove();
     private static void beginMove() {
          while(true) {
               /*if(mover.getLocation().x <= 0) {
                    xDir = (-xDir);
               if(mover.getLocation().y <= 0) {
                    yDir = (-yDir);
               if(mover.getLocation().x >= Toolkit.getDefaultToolkit().getScreenSize().width) {
                    xDir = (-xDir);
               if(mover.getLocation().y >= Toolkit.getDefaultToolkit().getScreenSize().height) {
                    yDir = (-yDir);
               mover.move(xDir, yDir);
               try {Thread.sleep(sleepTime);} catch (InterruptedException e) {}
import java.awt.Color;
import java.awt.Point;
import javax.swing.JFrame;
public class Mover extends JFrame {
     public JFrame mover = new JFrame();
     public Mover() {
          mover.setSize(100, 100);
          mover.setUndecorated(true);
          mover.getContentPane().setBackground(Color.green);
          mover.setLocation(100, 100);
          mover.setVisible(true);
     public void move(int xAmt, int yAmt) {
          mover.setLocation((mover.getLocation().x + xAmt), (mover.getLocation().y + yAmt));
}

Answer 1

Looks like I spoke to soon... After I changed the mover class as you did, this is thrown:
Exception in thread "main" java.lang.StackOverflowError
     at java.awt.Component.setLocation(Unknown Source)
     at Mover.move(Mover.java:16)It prints the last two lines about 500 times (literally) then quits. Line 16 is setLocation(getX() + xAmt, getY() + yAmt); and the error goes away if this is removed.
When I try to move the frame in the mover class (mover.setLocation(10, 10);), nothing happens.
EDIT: It works when I use setBounds(). Why doesn't setLocation work???
Edited by: crimsondynamo329 on Oct 20, 2009 2:19 PM