运行java时，窗体在屏幕中间显示的代码

    import java.awt.*;

    int   width=0;
    int   height=0;
    width=Toolkit.getDefaultToolkit().getScreenSize().width;
    height=Toolkit.getDefaultToolkit().getScreenSize().height;

    frame.setLocation((width - frameSize.width) / 2,   (height - frameSize.height) / 2);
frame.setVisible(true);