如何设计窗体到屏幕中间

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

            //获取电脑屏幕的长和宽

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

           //获取窗体的长与宽

            Dimension a=jf.getSize();

          //将窗体设置到指定坐标处

            jf.setLocation((width-a.width)/2, (height-a.height)/2);
            setLocationRelativeTo(null);