java swing Jpanel

“` 
 package com.js; 
 import java.awt.*; 
 import javax.swing.*; 
 public class Java_3_swing_8_JPanel extends JFrame { 
 public Java_3_swing_8_JPanel(){ 
 Container c = getContentPane(); 
 // 将整个容器设置为2行1列的网格布局 
 c.setLayout(new GridLayout(2,1,10,10)); 
 // 初始化 一个面板，设置 1行 3列 的网格布局 
 JPanel p1 = new JPanel(new GridLayout(1,3,10,10)); 
 JPanel p2 = new JPanel(new GridLayout(1,2,10,10)); 
 JPanel p3 = new JPanel(new GridLayout(1,2,10,10)); 
 JPanel p4 = new JPanel(new GridLayout(2,1,10,10)); 
 p1.add(new JButton(“1”)); 
 p1.add(new JButton(“2”)); 
 p1.add(new JButton(“3”)); 
 p2.add(new JButton(“1”)); 
 p2.add(new JButton(“2”)); 
 p3.add(new JButton(“1”)); 
 p3.add(new JButton(“2”)); 
 p4.add(new JButton(“1”)); 
 p4.add(new JButton(“2”)); 
 c.add(p1); 
 c.add(p2); 
 c.add(p3); 
 c.add(p4); 
 setSize(500,500); 
 setVisible(true); 
 setTitle(“面板布局，先面板，然后网格”); 
 setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);}
public static void main(String[] args) {
    // TODO 自动生成的方法存根
    new Java_3_swing_8_JPanel();
}}
“`