Java Jpanel_3一直报错

Java Jpanel_3一直报错，要怎么改啊


package demo;

import java.awt.GridLayout;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class ButtonGridLayout {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Button Grid Layout");
        JPanel jpanel_3 = new JPanel(new GridLayout(2, 3));
        JButton button1 = new JButton("农场认养");
        JButton button2 = new JButton("农场监控");
        JButton button3 = new JButton("养殖数量");
        JButton button4 = new JButton("农场直播");
        JButton button5 = new JButton("拼团促销");
        JButton button6 = new JButton("积分商城");
        JLabel backgroud;
        ImageIcon img=new ImageIcon("src/img/1.jpg");
        backgroud=new JLabel(img);
        backgroud.setBounds(0,0,img.getIconWidth(),img.getIconHeight());
        

        final int WIDTH=1000;//宽高
        final int HEIGHT=713;
        javax.swing.JPanel jpanel_1;//放图片的和其他盘子的
        javax.swing.JPanel jpanel_2;//只放标题
        javax.swing.JPanel jpanel_3;
        jpanel_3.add(button1);
        jpanel_3.add(button2);
        jpanel_3.add(button3);
        jpanel_3.add(button4);
        jpanel_3.add(button5);
        jpanel_3.add(button6);
        jpanel_1.add(backgroud);

        frame.add(jpanel_3);
        frame.add(jpanel_1);
        frame.pack();
        frame.setVisible(true);
    }
}

重复定义jpanel_3

img