麻烦解释一下各代码的意思，整体思路

Question

package wuziqi1;
import java.awt.Checkbox;
import java.awt.CheckboxGroup;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class wuziqi1 extends JFrame{
CheseGame CG;
wuziqi1 ()
{
this.CG= new CheseGame();
addMouseListener(CG);
add(CG);
}
public static void main(String[] args) {
wuziqi1 fivechese= new wuziqi1 ();
fivechese.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fivechese.setSize(900, 700);
fivechese.setTitle("五子棋");
fivechese.setVisible(true);
fivechese.setResizable(true);
}
}
class CheseGame extends JPanel implements MouseListener,ItemListener
{
int [][]map = new int[20][20];
Color []color = {Color.BLACK,Color.WHITE,Color.GREEN};
int x = -1;
int y = -1;
int flag = 1;
int winner = 3;
JButton btn1 = new JButton("开始");
JButton btn2 = new JButton("再来一局");
CheckboxGroup cbg = new CheckboxGroup();
Checkbox chb1 = new Checkbox("黑棋先开始",cbg,true);
Checkbox chb2 = new Checkbox("白棋先开始",cbg,false);
public void itemStateChanged(ItemEvent ie) {
if(chb1.getState())
{
flag = 1;
}
else
{
flag = 2;
}
}
class GameStart implements ActionListener
{
public void actionPerformed(ActionEvent ae)
{

         if(ae.getSource() == btn1)
         {
             start();
             repaint();
             btn1.setEnabled(false);
             btn2.setEnabled(true);
             chb1.setEnabled(false);
             chb2.setEnabled(false);
         }
         if(ae.getSource() == btn2)
         {
             start();
             repaint();
             chb1.setEnabled(true);
             chb2.setEnabled(true);
         }
    }
}
CheseGame()
{  

    this.setLayout(null);
    chb1.setBounds(650, 50, 100, 30);
    chb2.setBounds(650, 100, 100, 30);
    chb1.addItemListener(this);
    chb2.addItemListener(this);
    btn1.setBounds(650,150,100,30);
    btn1.addActionListener(new GameStart()); 
    btn2.setBounds(650, 200, 100, 30);
    btn2.addActionListener(new GameStart());
    btn2.setEnabled(false);
    this.add(btn1);
    this.add(btn2);
    this.add(chb1);
    this.add(chb2);
}
void start()
{
    for(int i = 0;i < 20;i++)
        for(int j = 0;j < 20;j++)
            map[i][j] = 0;
    winner = 0;
}
Boolean win(int x,int y)
{
    int score = 1;
         for(int i = x;i < x+4;)
         {
             if(i == 19)
                 break;
             if(map[i][y] != map[++i][y])
                break;
             score++;
         }
         for(int i = x;i > x-4;)
         {
             if(i == 0)
                 break;
             if(map[i][y] != map[--i][y])
                break;
             score++;
         } 
        if(score >= 5)
             return true;
        else
             score = 1;
        for(int j = y; j < y+4;)
        {
            if(j == 19)
                break;
            if(map[x][j] != map[x][++j])
                break;
            score++;
        }
        for(int j = y; j > y-4;)
        {
            if(j == 0)
                break;
            if(map[x][j] != map[x][--j])
                break;
            score++;
        } 
        if(score >= 5)
             return true;
        else
             score = 1;
        for(int i = x;i < x+4;)
            for(int j = y;j < y+4;)
            {
                if(i == 19 || y == 19)
                {i = x+4; break;}
                if(map[i][j] != map[++i][++j])
                {
                    i = x+4;
                    break;
                }
                score++;
            }
          for(int i = x;i > x-4;)
            for(int j = y;j > y-4;)
            {
                if(i == 0||j==0)
                {i = x-4; break;}
                if(map[i][j] != map[--i][--j])
                {
                    i = x-4;
                    break;
                }
                score++;
            } 
          if(score >= 5)
             return true;
         else
             score = 1;
        for(int i = x;i > x-4;)
            for(int j = y;j < y+4;)
            {
                if(i==0 || j==19)
                { i = x-4;break;}
                if(map[i][j] != map[--i][++j])
                {
                    i = x-4;
                    break;
                }
                score++;
            }  
        for(int i = x;i < x+4;)
            for(int j = y;j > y-4;)
            {
                if(i==19||j==0)
                { i = x+4;break;}
                if(map[i][j] != map[++i][--j])
                {
                    i = x + 4;
                    break;
                }
                score++; 
            } 
        if(score >= 5)
             return true;
        else
             return false;
}
public void paintComponent(Graphics g)
 {
       super.paintComponent(g);
       setBackground(color[2]);
       for(int i = 1;i <= 20;i++)
       {
           g.setColor(color[0]);
           g.drawLine(30, i*30 ,600 , i*30);
           g.drawLine(i*30,30, i*30, 600);
       }
       for(int i = 0;i < 20;i++)
           for(int j = 0;j < 20;j++)
           {
               if(map[i][j] == 1)
               { 
                   g.setColor(color[0]);
                   g.fillOval((i+1)*30-15, (j+1)*30-15, 30, 30);
               }
               if(map[i][j] == 2)
               {
                   g.setColor(color[1]);
                   g.fillOval((i+1)*30-15, (j+1)*30-15, 30, 30);
               }
           }
       Font font = new Font("",30,50);
       g.setFont(font);
       if(winner == 1)
       {
           g.setColor(color[0]);
           g.drawString("黑棋胜", 650, 300);
       }
       if(winner == 2)
       { 
           g.setColor(color[1]);
           g.drawString("白棋胜", 650, 300);
       }
 }
public void mouseClicked(MouseEvent me) {
}
public void mousePressed(MouseEvent me) {
    if(winner == 0)
    {
        x = me.getX();
        y = me.getY();
        chb1.setEnabled(false);
        chb2.setEnabled(false);
    }
    x = (int)(x/30)-1;
    y = (int)((y-15)/30)-1;
    if(x>=0&&x<=19&&y>=0&&y<=19)
    {
        if(flag == 1&&map[x][y] == 0)
        {
            map[x][y] = 1;
            if(win(x,y))
                winner = 1;
            flag = 2;
        }
        else
            if(flag == 2&&map[x][y] == 0)
        {
            map[x][y] = 2;
             if(win(x,y))
                 winner = 2;
            flag = 1;
        }
    }
    repaint();
}
@Override
public void mouseReleased(MouseEvent me) {
   // throw new UnsupportedOperationException("Not supported yet.");
}
@Override
public void mouseEntered(MouseEvent me) {
   // throw new UnsupportedOperationException("Not supported yet.");
}
@Override
public void mouseExited(MouseEvent me) {
   // throw new UnsupportedOperationException("Not supported yet.");
}

}

Answer 1

package test;

import java.awt.Checkbox;
import java.awt.CheckboxGroup;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Wuziqi1 extends JFrame {
    private static final long serialVersionUID = 8466850317892978450L;

    CheseGame CG;

    Wuziqi1() {
        this.CG = new CheseGame();
        // 为窗口增加鼠标监听
        addMouseListener(CG);
        add(CG);
    }

    // 执行的主函数. 主要是初始化 窗口用的. 
    public static void main(String[] args) {
        Wuziqi1 fivechese = new Wuziqi1();
        // 设置程序退出方式 . (窗口关闭 即 关闭程序)
        fivechese.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        // 设置窗口尺寸
        fivechese.setSize(900, 700);
        // 设置窗口的标题
        fivechese.setTitle("五子棋");
        // 设置窗口是否课件
        fivechese.setVisible(true);
        // 设置窗口是否可以拖拽调整窗口尺寸
        fivechese.setResizable(true);
    }
}

class CheseGame extends JPanel implements MouseListener, ItemListener {
    private static final long serialVersionUID = 4244441458513824552L;

    // map 用于 存储 棋子信息
    int[][] map = new int[20][20];
    Color[] color = { Color.BLACK, Color.WHITE, Color.GREEN };
    int x = -1;
    int y = -1;
    // 1 黑棋落棋, 2.白棋落棋 
    int flag = 1;
    // 五局三胜制
    int winner = 3;
    JButton btn1 = new JButton("开始");
    JButton btn2 = new JButton("再来一局");
    // 2个单选按钮
    CheckboxGroup cbg = new CheckboxGroup();
    Checkbox chb1 = new Checkbox("黑棋先开始", cbg, true);
    Checkbox chb2 = new Checkbox("白棋先开始", cbg, false);

    public void itemStateChanged(ItemEvent ie) {
        if (chb1.getState()) {
            flag = 1;
        } else {
            flag = 2;
        }
    }

    // 为 开始 按钮 和 再来一局按钮 设置 监听事件
    class GameStart implements ActionListener {
        public void actionPerformed(ActionEvent ae) {
            if (ae.getSource() == btn1) { // 开始按钮
                // 执行 开始 的处理逻辑
                start();
                // 重绘窗口
                repaint();
                // 开始按钮 置灰
                btn1.setEnabled(false);
                // 再来一句 可以使用
                btn2.setEnabled(true);
                // 单选按钮 置灰
                chb1.setEnabled(false);
                chb2.setEnabled(false);
            }
            if (ae.getSource() == btn2) {
                // 执行 开始 的处理逻辑
                start();
                // 重绘窗口
                repaint();
                // 单选按钮 可以使用
                chb1.setEnabled(true);
                chb2.setEnabled(true);
            }
        }
    }

    // 设置窗口布局
    CheseGame() {
        // 设置布局方式  null (标识通过 定位 布局)
        this.setLayout(null);
        // setBounds(x,y,width,height);
        chb1.setBounds(650, 50, 100, 30);
        chb2.setBounds(650, 100, 100, 30);
        chb1.addItemListener(this);
        chb2.addItemListener(this);
        btn1.setBounds(650, 150, 100, 30);
        btn1.addActionListener(new GameStart());
        btn2.setBounds(650, 200, 100, 30);
        btn2.addActionListener(new GameStart());
        btn2.setEnabled(false);
        this.add(btn1);
        this.add(btn2);
        this.add(chb1);
        this.add(chb2);
    }
    // 开始
    void start() {
        // 将 map 清空, 也就是清空棋盘上所有的棋子
        for (int i = 0; i < 20; i++)
            for (int j = 0; j < 20; j++)
                map[i][j] = 0;
        // 胜负调为0
        winner = 0;
    }

    // 检查 黑棋 或 白棋 的胜负问题. 
    Boolean win(int x, int y) {
        int score = 1;
        // map[i][y] != map[++i][y] 类似的这种都是为了检查 棋子 是否是相同的颜色
        // if (i == 19) 棋盘大小20个.对应下标19. 所以 判断19是为了防止下标溢出

        // 从放置的棋子开始, 向右检查 有多少个 相连的同色棋子
        for (int i = x; i < x + 4;) {
            if (i == 19)
                break;
            if (map[i][y] != map[++i][y])
                break;
            score++;
        }
        // 从放置的棋子开始, 向左检查 有多少个 相连的同色棋子
        for (int i = x; i > x - 4;) {
            if (i == 0)
                break;
            if (map[i][y] != map[--i][y])
                break;
            score++;
        }
        // 如果相连的数目大于等于5, 当前落子的一方获胜
        if (score >= 5)
            return true;
        else
            score = 1;
        // 同上, 不过是 检查 纵向 相连的棋子数目
        for (int j = y; j < y + 4;) {
            if (j == 19)
                break;
            if (map[x][j] != map[x][++j])
                break;
            score++;
        }
        for (int j = y; j > y - 4;) {
            if (j == 0)
                break;
            if (map[x][j] != map[x][--j])
                break;
            score++;
        }
        // 如果相连的数目大于等于5, 当前落子的一方获胜
        if (score >= 5)
            return true;
        else
            score = 1;
        // 同理, 不过现在是 斜着 判断. 所以下标 需要 [++i][++j]
        for (int i = x; i < x + 4;)
            for (int j = y; j < y + 4;) {
                if (i == 19 || y == 19) {
                    i = x + 4;
                    break;
                }
                if (map[i][j] != map[++i][++j]) {
                    i = x + 4;
                    break;
                }
                score++;
            }
        for (int i = x; i > x - 4;)
            for (int j = y; j > y - 4;) {
                if (i == 0 || j == 0) {
                    i = x - 4;
                    break;
                }
                if (map[i][j] != map[--i][--j]) {
                    i = x - 4;
                    break;
                }
                score++;
            }
        // 如果相连的数目大于等于5, 当前落子的一方获胜
        if (score >= 5)
            return true;
        else
            score = 1;
        // 同理
        for (int i = x; i > x - 4;)
            for (int j = y; j < y + 4;) {
                if (i == 0 || j == 19) {
                    i = x - 4;
                    break;
                }
                if (map[i][j] != map[--i][++j]) {
                    i = x - 4;
                    break;
                }
                score++;
            }
        for (int i = x; i < x + 4;)
            for (int j = y; j > y - 4;) {
                if (i == 19 || j == 0) {
                    i = x + 4;
                    break;
                }
                if (map[i][j] != map[++i][--j]) {
                    i = x + 4;
                    break;
                }
                score++;
            }
        // 如果相连的数目大于等于5, 当前落子的一方获胜
        if (score >= 5)
            return true;
        else
            return false;
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        // 绘制棋盘底色
        setBackground(color[2]);
        // 绘制棋盘格
        for (int i = 1; i <= 20; i++) {
            g.setColor(color[0]);
            g.drawLine(30, i * 30, 600, i * 30);
            g.drawLine(i * 30, 30, i * 30, 600);
        }
        // 绘制棋盘上棋子
        for (int i = 0; i < 20; i++)
            for (int j = 0; j < 20; j++) {
                if (map[i][j] == 1) {
                    g.setColor(color[0]);
                    g.fillOval((i + 1) * 30 - 15, (j + 1) * 30 - 15, 30, 30);
                }
                if (map[i][j] == 2) {
                    g.setColor(color[1]);
                    g.fillOval((i + 1) * 30 - 15, (j + 1) * 30 - 15, 30, 30);
                }
            }
        Font font = new Font("", 30, 50);
        g.setFont(font);
        // 出现胜负的时候, 绘制获胜方信息
        if (winner == 1) {
            g.setColor(color[0]);
            g.drawString("黑棋胜", 650, 300);
        }
        if (winner == 2) {
            g.setColor(color[1]);
            g.drawString("白棋胜", 650, 300);
        }
    }

    public void mouseClicked(MouseEvent me) {
    }

    public void mousePressed(MouseEvent me) {
        // 如果还没有获胜方
        if (winner == 0) {
            x = me.getX();
            y = me.getY();
            chb1.setEnabled(false);
            chb2.setEnabled(false);
        }
        // 通过坐标轴 计算 当前点击位置 落子 对应map中的下标
        x = (int) (x / 30) - 1;
        y = (int) ((y - 15) / 30) - 1;
        if (x >= 0 && x <= 19 && y >= 0 && y <= 19) {
            if (flag == 1 && map[x][y] == 0) {
                // 记录落子信息
                map[x][y] = 1;
                // 检查当前落子后的胜负
                if (win(x, y))
                    winner = 1;
                flag = 2;
            } else if (flag == 2 && map[x][y] == 0) {
                // 记录落子信息
                map[x][y] = 2;
                // 检查当前落子后的胜负
                if (win(x, y))
                    winner = 2;
                flag = 1;
            }
        }
        repaint();
    }

    @Override
    public void mouseReleased(MouseEvent me) {
        // throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public void mouseEntered(MouseEvent me) {
        // throw new UnsupportedOperationException("Not supported yet.");
    }

    @Override
    public void mouseExited(MouseEvent me) {
        // throw new UnsupportedOperationException("Not supported yet.");
    }
}