java窗体居中

import java.awt.Toolkit;

private void centerShell(Shell shell)
{
         //得到屏幕的宽度和高度
         int screenHeight = Toolkit.getDefaultToolkit().getScreenSize().height;
         int screenWidth = Toolkit.getDefaultToolkit().getScreenSize().width;
         //得到Shell窗口的宽度和高度
         int shellHeight = shell.getBounds().height;
         int shellWidth = shell.getBounds().width;
         //如果窗口大小超过屏幕大小，让窗口与屏幕等大
         if(shellHeight > screenHeight)
                   shellHeight = screenHeight;
         if(shellWidth > screenWidth)
                  shellWidth = screenWidth;
        //让窗口在屏幕中间显示
        shell.setLocation(( (screenWidth - shellWidth) / 2),((screenHeight - shellHeight) / 2) );
}