Java：JFrame. Setlocationrelativeto (null) is not available as Ubuntu 10.04 / Gnome 2.30 2 window centered openjdk 1.6 0_ eighteen

Example code:

JFrame jFrame = new JFrame("Test");
    jFrame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
    jFrame.setLocationRelativeTo(null);
    jFrame.setSize(600,600);
    jFrame.pack();
    // jFrame.setLocationRelativeTo(null); // same results
    jFrame.setVisible(true);

screenshot http://img193.imageshack.us/img193/5296/screenshotrev.png

Is this openjdk's fault? I remember hearing that it is not as good as sun's, but because it has become the standard of Ubuntu, or the standard I decided to use with it The program may run on windows, so I think I want to check there... Any simple way to solve this platform independent way without destroying where it already works?

Solution

One way is to position the window manually Place the following code after calling pack ()

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Point middle = new Point(screenSize.width / 2,screenSize.height / 2);
Point newLocation = new Point(middle.x - (jFrame.getWidth() / 2),middle.y - (jFrame.getHeight() / 2));
jFrame.setLocation(newLocation);

Disclaimer, this is only tested on windows

In addition, you should always use setpreferredsize() instead of setsize()