首先感谢yinnowl提供的文章midp1.0-五子棋1.1，我是一个j2me的初学者，看了yinnowl的这篇文章后，有些自己的想法，所以就冒昧和大家分享，请大家批评指正。

           我的思路是把midp1.0-五子棋1.1改成在midp2.0上实现，同时感觉原文在判断胜负的时候比较慢做了下优化，原文链接请点击这里。

           关于详细的解释，原文已经都有，我这也不敢班门弄斧，只给出我自己用到的4个类：
1.midlet 主类gobang.java     
package hero;

import javax.microedition.midlet.midlet;
import javax.microedition.lcdui.display;
import javax.microedition.lcdui.image;

public class gobang
    extends midlet
     {

  startform startform;
  private display dispaly;
  public static  gobang instance;

  public gobang() {
    instance = this;
    dispaly = display.getdisplay(this);
  }

  protected void startapp() {
   startform = new startform();
    dispaly.setcurrent(startform);

  }

  protected void pauseapp() {

  }

  protected void destroyapp(boolean uncondition) {

  }

 protected void quitapp(){
   instance.destroyapp(true);
    instance.notifydestroyed();
    instance = null;

 }

  //读取并添加图片
 public static image createimage(string name) {
   image aimage = null;
   try {
     aimage = image.createimage(name);
   }
   catch (exception e) {
   }
   return aimage;
 }

}
2.棋子类 chesses .java
package hero;

public class chesses {
  boolean isplayer1;
 public chesses(){

 }

 public chesses(boolean isplayer1) {
        this.isplayer1=isplayer1;
    }

}
3.图形加载类  startform.java  （一个过渡界面）
package hero;

import javax.microedition.lcdui.form;
import javax.microedition.lcdui.commandlistener;
import javax.microedition.lcdui.command;
import javax.microedition.lcdui.image;
import javax.microedition.lcdui.imageitem;
import javax.microedition.lcdui.display;
import javax.microedition.lcdui.displayable;
import javax.microedition.lcdui.graphics;

public class startform extends form implements commandlistener {
  private static command exitcmd;
  private static command okcmd;
  private image startimage;
 protected gobang gobang;
 private gobangcanvas gobangcanvas;
  //显示程序的启动画面//
  public startform() {
    super("");
    okcmd = new command("进入", command.ok, 1);
    exitcmd = new command("离开", command.exit, 1);

    image startimage = gobang.createimage("/res/me.png");

    this.addcommand(okcmd);
    this.addcommand(exitcmd);
    this.setcommandlistener(this);
    //graphics g=getgraphics();
    this.append(new imageitem(null, startimage, imageitem.layout_center, null)) ;
  //  this.append(startimage);

    display.getdisplay(gobang.instance).setcurrent(this);

  }
  public void commandaction(command command, displayable displayable) {
    if (command == okcmd)
    {
      gobangcanvas = new gobangcanvas();
    display.getdisplay(gobang.instance).setcurrent(gobangcanvas);
    gobangcanvas.startup();

    }
   if (command == exitcmd) {
      gobang.instance.quitapp();
    }
  }
}
4.主要实现类
package hero;

import javax.microedition.lcdui.graphics;
import javax.microedition.lcdui.alert;
import javax.microedition.lcdui.alerttype;
import javax.microedition.lcdui.display;
import javax.microedition.lcdui.game.gamecanvas;
import javax.microedition.lcdui.command;
import javax.microedition.lcdui.commandlistener;
import javax.microedition.lcdui.displayable;

public class gobangcanvas
    extends gamecanvas
    implements runnable, commandlistener {
  protected gobang gobang;
  private graphics g;
  int empty; //游戏界面到屏幕边缘的留空
  int canvasw, canvash; //画布的长和宽
  int chesslength; //棋子的直径
  int chessmaplength, chessmapgrid, chessgridlength; //棋盘的边长，棋盘一边格子数，每格宽度
  int chessmapx, chessmapy; //棋盘左上角x,y坐标
  int selectedx, selectedy; //选择框在棋盘格局上的x,y位置
  boolean isplayer1; //是否是玩家1
  chesses[][] chesses; //棋子数组
  boolean newgame; //是否是新的游戏
  boolean isplay; //是否游戏进行中
  private command exitcommand;
  private command startcommand;
  int player1win, player2win;

  public gobangcanvas() {
    super(true);
    newgame = true;
    empty = 10;
    canvasw = getwidth() - empty;
    canvash = getheight() - empty;
    chessmapgrid = 15;
    chesses = new chesses[chessmapgrid + 1][chessmapgrid + 1];
    if (canvasw > canvash) {
      chessmaplength = canvash - canvash % chessmapgrid;
      chessmapx = (canvasw - chessmaplength) / 2 + empty / 2;
      chessmapy = (canvash % chessmapgrid) / 2 + empty / 2;
    }
    else {
      chessmaplength = canvasw - canvasw % chessmapgrid;
      chessmapx = (canvasw % chessmapgrid) / 2 + empty / 2;
      chessmapy = (canvash - chessmaplength) / 2 + empty / 2;
    }
    chessgridlength = chessmaplength / chessmapgrid;
    chesslength = chessgridlength - 1;
    selectedx = selectedy = chessmapgrid / 2;
    isplayer1 = true;
    exitcommand = new command("退出", command.exit, 1);
    startcommand = new command("开始", command.screen, 1);
    addcommand(startcommand);
    addcommand(exitcommand);
    setcommandlistener(this);
  }

  public void startup() {
    isplay = true;
    thread thread = new thread(this);
    thread.start();
  }

  protected void paintmap(graphics g) {
    for (int i = 0; i < chessmapgrid; i++) {
      for (int j = 0; j < chessmapgrid; j++) {
        g.setcolor(128, 128, 128);
        g.drawrect(chessmapx + j * chessgridlength,
                   chessmapy + i * chessgridlength,
                   chessgridlength, chessgridlength);
        if (chesses[i][j] != null) {

          if (chesses[i][j].isplayer1) {
            g.setcolor(255, 255, 255);
          }
          else {
            g.setcolor(255, 0, 0);
          }

          g.fillarc(chessmapx + j * chessgridlength - chesslength / 2,
                    chessmapy + i * chessgridlength - chesslength / 2,
                    chesslength, chesslength, 0, 360);
        }

      }
    }
  }

  protected void paintselected(graphics g) {
    g.setcolor(0, 0, 255);
    g.drawrect(chessmapx + selectedx * chessgridlength - chessgridlength / 2,
               chessmapy + selectedy * chessgridlength - chessgridlength / 2,
               chessgridlength, chessgridlength);
  }

  protected void paintplayer(graphics g, boolean isplayer1) {
    if (isplayer1) {
      g.setcolor(255, 255, 255);
    }
    else {
      g.setcolor(255, 0, 0);
    }
    g.drawrect(1, 1, getwidth() - 2, getheight() - 2);
    g.drawrect(2, 2, getwidth() - 4, getheight() - 4);
    g.drawrect(3, 3, getwidth() - 6, getheight() - 6);
  }

  public void paint(graphics g) {
    g.setcolor(0x00000000);
    g.fillrect(0, 0, getwidth(), getheight());
    paintplayer(g, isplayer1);
    paintselected(g);
    paintmap(g);
    flushgraphics();
  }

  private void init() {
    if (newgame) {
      chesses = new chesses[chessmapgrid + 1][chessmapgrid + 1];
      isplayer1 = true;
      selectedx = selectedy = chessmapgrid / 2;
    }
  }

  public void run() {

    g = getgraphics();
    while (isplay) {
      try {
        input(g);
        paint(g);
        thread.sleep(500);
      }
      catch (exception e) {
        e.printstacktrace();
      }
    }
  }

  public void input(graphics g) {

    int keystates = getkeystates();
    if ( (keystates & left_pressed) != 0) {
      selectedx = (--selectedx + chessmapgrid + 1) % (chessmapgrid + 1);
    }
    else if ( (keystates & right_pressed) != 0) {
      selectedx = (++selectedx) % (chessmapgrid + 1);
    }
    else if ( (keystates & up_pressed) != 0) {
      selectedy = (--selectedy + chessmapgrid + 1) % (chessmapgrid + 1);
    }
    else if ( (keystates & down_pressed) != 0) {
      selectedy = (++selectedy) % (chessmapgrid + 1);
    }
    else if ( (keystates & fire_pressed) != 0) {

      if (chesses[selectedy][selectedx] == null) {
        chesses[selectedy][selectedx] = new chesses(this.isplayer1);

        if (checkwin()) {
          string winner;
          if (isplayer1) {
            winner = "白方胜利";
            player1win++;
          }
          else {
            winner = "红方胜利";
            player2win++;
          }

          alert winalert = new alert("",
                                     winner + "/n白方  " + player1win + " : " +
                                     player2win + "  红方",
                                     null, alerttype.info);
          winalert.settimeout(alert.forever);
          display.getdisplay(gobang.instance).setcurrent(winalert);
          init();
          flushgraphics();
          // repaint();
        }
        this.isplayer1 = !this.isplayer1; //切换下棋方
      }
    }
    flushgraphics();
    // repaint();
  }

  private boolean checkwin() {
    int num = 1;
    if (num < 5) {
      num = 1;
      for (int i = 1; i <= 4; i++) {
        if (isplayer1(selectedx - i, selectedy)) {
          num++;
        }
        else if(isplayer1(selectedx + i, selectedy)) {
          num++;
        }else{
          break;
        }
      }

    }
    if (num < 5) {
      num = 1;
      for (int i = 1; i <= 4; i++) {
        if (isplayer1(selectedx, selectedy - i)) {
          num++;
        }
        else if(isplayer1(selectedx, selectedy + i)) {
          num++;
        }
        else {
          break;
        }
      }
    }
    if (num < 5) {
      num = 1;
      for (int i = 1; i <= 4; i++) {
        if (isplayer1(selectedx - i, selectedy - i)) {
          num++;
        }
        else if (isplayer1(selectedx + i, selectedy + i)) {
          num++;
        }
        else {
          break;
        }
      }

    }
    if (num < 5) {
      num = 1;
      for (int i = 1; i <= 4; i++) {
        if (isplayer1(selectedx + i, selectedy - i)) {
          num++;
        }
        else if(isplayer1(selectedx - i, selectedy + i)) {
          num++;
        }
        else {
          break;
        }
      }
    }
    if (num >= 5) {
      return true;
    }
    else {
      return false;
    }
  }

  private boolean isplayer1(int y, int x) {
    if (x <= 15 && x >= 0 && y <= 15 && y >= 0 && chesses[x][y] != null) {
      if (chesses[x][y].isplayer1 == this.isplayer1) {
        return true;
      }
      else {
        return false;
      }
    }
    else {
      return false;
    }
  }

  public void commandaction(command c, displayable dpa) {

    if (c.equals(startcommand)) {
      init();
      startup();
    }
    else if (c.equals(exitcommand)) {
      gobang.instance.startapp();
    }
  }

}

以上代码在wtk2.2下调试通过，最后恳请大家批评指正。