Bagaimana untuk melaksanakan permainan tiga keping mudah menggunakan Java?

import java.util.Random;
import javax.swing.*;
public class Main {
   public static boolean check(StringBuffer st,int pos){   //检查pos上的棋子有没有获胜
      char des=st.charAt(pos);
      char []s=new char[10];
      for(int i=1;i<=9;i++) s[i]=st.charAt(i);
      if((s[3]==des&&s[6]==des&&s[9]==des)||
      (s[1]==des&&s[4]==des&&s[7]==des)||
      (s[2]==des&&s[5]==des&&s[8]==des)||
      (s[1]==des&&s[3]==des&&s[2]==des)||
      (s[6]==des&&s[4]==des&&s[5]==des)||
      (s[9]==des&&s[7]==des&&s[8]==des)||
      (s[1]==des&&s[5]==des&&s[9]==des)||
      (s[3]==des&&s[5]==des&&s[7]==des)) return true;
      return false;
   }
   public static void main(String[] args) {
      StringBuffer s= new StringBuffer("0123456789");
      String tp;
      for(int i=0;i<=5;){
         int k=-1;
         tp=JOptionPane.showInputDialog("---------------------------\n|    "+s.charAt(1)+"    |    "+s.charAt(2)+"    |    "+s.charAt(3)+"    |\n---------------------------\n|    "+s.charAt(4)+"    |    "+s.charAt(5)+"    |    "+s.charAt(6)+"    |\n---------------------------\n|    "+s.charAt(7)+"    |    "+s.charAt(8)+"    |    "+s.charAt(9)+"    |\n---------------------------\n"+"请输入落子位置(1~9)：");
         boolean f=true;
         if(tp.length()==1){
            k=tp.charAt(0)-&#39;0&#39;;
            if(k>=1&&k<=9){
               if(s.charAt(k)>=&#39;1&#39;&&s.charAt(k)<=&#39;9&#39;){
                  i++;        //有效下棋
                  f=false;
               }
            }
         }
         while(f){
            tp=JOptionPane.showInputDialog("---------------------------\n|    "+s.charAt(1)+"    |    "+s.charAt(2)+"    |    "+s.charAt(3)+"    |\n---------------------------\n|    "+s.charAt(4)+"    |    "+s.charAt(5)+"    |    "+s.charAt(6)+"    |\n---------------------------\n|    "+s.charAt(7)+"    |    "+s.charAt(8)+"    |    "+s.charAt(9)+"    |\n---------------------------\n"+"输入错误，请重新输入落子的位置：");
            if(tp.length()==1){
               k=tp.charAt(0)-&#39;0&#39;;
               if(k>=1&&k<=9){
                  if(s.charAt(k)>=&#39;1&#39;&&s.charAt(k)<=&#39;9&#39;){
                     i++;        //有效下棋
                     f=false;
                  }
               }
            }
         }
         //在k处落子
         s.replace(k,k+1,"O");
         if(check(s,k)){
            //获胜
            JOptionPane.showMessageDialog(null,"---------------------------\n|    "+s.charAt(1)+"    |    "+s.charAt(2)+"    |    "+s.charAt(3)+"    |\n---------------------------\n|    "+s.charAt(4)+"    |    "+s.charAt(5)+"    |    "+s.charAt(6)+"    |\n---------------------------\n|    "+s.charAt(7)+"    |    "+s.charAt(8)+"    |    "+s.charAt(9)+"    |\n---------------------------\n"+"恭喜你，你赢了！");
            break;
         }
         //电脑随机落子
         if(i==5) {
            JOptionPane.showMessageDialog(null,"---------------------------\n|    "+s.charAt(1)+"    |    "+s.charAt(2)+"    |    "+s.charAt(3)+"    |\n---------------------------\n|    "+s.charAt(4)+"    |    "+s.charAt(5)+"    |    "+s.charAt(6)+"    |\n---------------------------\n|    "+s.charAt(7)+"    |    "+s.charAt(8)+"    |    "+s.charAt(9)+"    |\n---------------------------\n"+"平局！");
            break;
         }
         Random rs=new Random();
         k=rs.nextInt(9)+1;
         while(k<1||k>9||s.charAt(k)==&#39;*&#39;||s.charAt(k)==&#39;O&#39;) k=rs.nextInt(9)+1;
         s.replace(k,k+1,"*");
         if(check(s,k)){
            //电脑胜
            JOptionPane.showMessageDialog(null,"---------------------------\n|    "+s.charAt(1)+"    |    "+s.charAt(2)+"    |    "+s.charAt(3)+"    |\n---------------------------\n|    "+s.charAt(4)+"    |    "+s.charAt(5)+"    |    "+s.charAt(6)+"    |\n---------------------------\n|    "+s.charAt(7)+"    |    "+s.charAt(8)+"    |    "+s.charAt(9)+"    |\n---------------------------\n"+"你输了，再接再厉吧！");
            break;
         }
      }
   }
}