关于Swing类使用的疑惑 求大神指点

package lianxi;
import java.awt.*;
import import javax.swing.*;
public class Ckou extends JFrame {
    // 创建构造函数
    public Ckou() {
        // 设置窗口名
        setTitle("不管你信不信反正就是我弄出来的");
//        创建一个容器
        Container c=getContentPane();
        c.setLayout(new GridLayout(1,1,100,100));
//        创建一个标签
        JLabel bq=new JLabel("这是窗体",JLabel.CENTER);
//        设置一个网格
        JPanel p1=new JPanel(new GridLayout(2,2,10,10));
        // 获取图片所在URL
        URL lj = Ckou.class.getResource("dlam.jpg");
//        实例化图片
        Icon tp = new ImageIcon(lj);
//        将图片放入标签
        bq.setIcon(tp);
//        将标签放入网格
        p1.add(bq);
//        将网格放入容器
        c.add(p1);
        // 在标签中间放置文字
        bq.setHorizontalAlignment(SwingConstants.CENTER);
        // 设置标签不透明
        bq.setOpaque(true);
//        窗体可见
        setVisible(true);
//        窗口大小
        setSize(700,560);
//        关闭方式
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        
    }
}
// 将标签添加到容器中

package lianxi;

import java.awt.*;

import javax.swing.*;

public class Jp extends Ckou {
    public  Jp(){   
        Ckou a=    new Ckou();
//        Container c=getContentPane();
//        a.setLayout(new GridLayout(2,1,100,100));
        
//        JPanel p1=new JPanel(new GridLayout(2,4,100,100));
        JPanel p2=new JPanel(new GridLayout(1,1,10,10));
        
//        p1.add(bq);
        p2.add(new JButton("1"));
        p2.add(new JButton("2"));
        
        
//        a.add(a);  在容器中添加面板
        a.add(p2);                    
        a.add(p2);
//        setTitle("在这个窗体中使用了面板");
//        setSize(520, 200);
//        setVisible(true);
//        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
    }
   
    public static void main(String[] args) {   
        Jp q=new Jp();
    }
}