提示:the constructor JPanel(URL) is undefined错误,应该怎么改正
final JPanel operatePanel = new JPanel(this.getClass().getResource(
"/img/land_background.jpg"));
operatePanel.setLayout(new GridBagLayout());
getContentPane().add(operatePanel, BorderLayout.NORTH);
JPanel(URL) ,Jpanel这个构造函数没有这个方法,不支持这项,试试operatePanel .set...方法试试看