JAVA swing.JFrame 的屏幕居中代码

   JFrame frame = new JFrame("Data Display");        frame.setSize(630,430);        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();        Dimension frameSize = frame.getSize();        frame.setLocation( (screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);        // set frame visible is true, then we can see it.        frame.setVisible(true);