刚接触j2me, 在书上看到一个j2me的例子，一运行就抛出如下问题，

Running with storage root C:\Documents and Settings\ZW\j2mewtk\2.5.2\appdb\DefaultColorPhone
Running with locale: Chinese_People's Republic of China.936
Running in the identified_third_party security domain
java.lang.NoClassDefFoundError: myCanvas: com/nokia/mid/ui/FullCanvas
at com.sun.midp.midlet.MIDletState.createMIDlet(+29)
at com.sun.midp.midlet.Scheduler.schedule(+52)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+80)
Execution completed.
3399723 bytecodes executed
18 thread switches
1669 classes in the system (including system classes)
17741 dynamic objects allocated (538584 bytes)
4 garbage collections (462968 bytes collected)



附上源代码，请高手看一下是哪里的问题。


gameStart.java

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class gameStart extends MIDlet{
    public static gameStart midlet;
    public myCanvas mc;
    public gameStart()
    { gameStart.midlet=this;//全局入口对象
    }
public void startApp()
{
gameStart.midlet.startGame();
}
public void pauseApp()
{}
public void destroyApp(boolean f)
{}
public void startGame()
{mc=null;
mc=new myCanvas();
Display.getDisplay(this).setCurrent(mc);
}
public void exitGame()
{ this.notifyDestroyed();
}
}

---------------------------------------------------------------
import javax.microedition.lcdui.*;
import java.util.*;
import com.nokia.mid.ui.*;


public class myCanvas  extends FullCanvas {
    public Image offScreen;
    public Graphics offg;
    public int map[][]=new int[8][8];
    public Random r1;
    public Image imCricle,imMine;//pic
    public int px,py;
    public int mineNumber=10;//总雷数
    public boolean gameOver=false;//游戏是否结束
    public boolean gameWin=false;//游戏是否胜利
    public myCanvas()
    { offScreen=Image.createImage(176,208);
      offg=offScreen.getGraphics();
      try{
      imCricle=Image.createImage("/cricle.png");
      imMine=Image.createImage("/mine.png");
      }catch(Exception e){}
      r1=new Random();
      initMap();//初始化雷区
    }
    public void initMap()
    {
    for(int n=0;n<mineNumber;n++)
    {int tmp=Math.abs(r1.nextInt()%64);
    int row=tmp/8;//行
    int col=tmp%8;//列
    if(map[row][col]!=20)
    { map[row][col]=20;//将第row行第col列设成雷
    }
    else
    {n--;}
    }
    }
    public void drawMap()
    {offg.setColor(0xFFFFFF);
     offg.fillRect(0,0,176,208);
     offg.setColor(0);
     for(int i=0;i<8;i++)
     { for(int j=0;j<8;j++)
       {offg.drawRect(j*20,i*20,20,20);
       //如果翻开则显示这点周围的雷数
        if(map[i][j]!=20&&map[i][j]!=0&&map[i][j]!=10)
        {
         offg.drawString(" "+map[i][j],j*20,i*20,0);
        }
        else if(map[i][j]==10)
        {
         offg.drawString("  0",j*20,i*20,0);
        }
       }
     }
   
    }
    public void drawCricle()
    {
      offg.drawImage(imCricle,px,py,0);
    }
    public void drawOver()//绘制游戏结束
    { offg.setColor(0xFFFFFF);
      offg.fillRect(0,0,176,208);
      offg.setColor(0);
      offg.drawString("Game Over",30,30,0);
      for(int i=0;i<8;i++)
      {
        for(int j=0;j<8;j++)
        {if(map[i][j]==20)
         {offg.drawImage(imMine,j*20,i*20,0);}
         else
         {offg.drawRect(j*20,i*20,20,20);}
        }
      }
    }
    public void drawWin()//绘制游戏胜利
    {
    offg.setColor(0xFFFFFF);
        offg.fillRect(0,0,176,208);
        offg.setColor(0);
        offg.drawString("you Win",30,30,0);
    }
public void paint(Graphics g)
{drawMap();//绘制雷区
drawCricle();//绘制选框
if(gameOver){drawOver();}
if(gameWin){drawWin();}
offg.drawString("new game            exit",0,170,0);
g.drawImage(offScreen,0,0,0);
}
public void checkWin()
{  int count=0;//记录翻开的数量
for(int i=0;i<8;i++)
{
for(int j=0;j<8;j++)
{
   if(map[i][j]>0)
   { count++;
   }
}
}
if(count+this.mineNumber==64)
{ this.gameWin=true;
}

}
//map[r2][c2]周围的雷数
public int checkNum(int r2,int c2)
{int num=0;
//左上
if(r2-1>=0&&c2-1>=0)//判断是否有左上
{
  if(map[r2-1][c2-1]==20){num++;}
}
//上
if(r2-1>=0)
{
  if(map[r2-1][c2]==20)num++;
}
//右上
if(r2-1>=0&&c2+1<=7)
{
   if(map[r2-1][c2+1]==20)num++;
}
//左
if(c2-1>=0)
{
  if(map[r2][c2-1]==20)num++;
}
//右
if(c2+1<=7)
{
  if(map[r2][c2+1]==20)num++;
}
//左下
if(r2+1<=7&&c2-1>=0)
{ if(map[r2+1][c2-1]==20)num++;
}
//下
if(r2+1<=7)
{
if(map[r2+1][c2]==20)num++;
}
//右下
if(r2+1<=7&&c2+1<=7)
{
if(map[r2+1][c2+1]==20)num++;
}
return num;//这点周围的雷数
}
public void check(int row,int col)
{
if(map[row][col]==20)
{gameOver=true;}
else
{//判定这点周围的雷数
int k=this.checkNum(row,col);
if(k>0)//这点周围有类
{ map[row][col]=k;//显示这点周围的雷数
}
else//这点周围没有雷
{ map[row][col]=10;//翻开这一点
   //在判断这点周围的情况
   //左上
     if(row-1>=0&&col-1>=0)
     { if(map[row-1][col-1]<10){//判断是否被翻开
     check(row-1,col-1);
       }
     }
   //上
     if(row-1>=0)
     { if(map[row-1][col]<10){//判断是否被翻开
     check(row-1,col);
       }
     }
   //右上
     if(row-1>=0&&col+1<=7)
     { if(map[row-1][col+1]<10){//判断是否被翻开
     check(row-1,col+1);
       }
     }
   //左
     if(col-1>=0)
     { if(map[row][col-1]<10){//判断是否被翻开
     check(row,col-1);
       }
     }
   //右
     if(col+1<=7)
     { if(map[row][col+1]<10){//判断是否被翻开
     check(row,col+1);
       }
     }
   //左下
     if(row+1<=7&&col-1>=0)
     { if(map[row+1][col-1]<10){//判断是否被翻开
     check(row+1,col-1);
       }
     }
   //下
     if(row+1<=7)
     { if(map[row+1][col]<10){//判断是否被翻开
     check(row+1,col);
       }
     }
   //右下
     if(row+1<=7&&col+1<=7)
     { if(map[row+1][col+1]<10){//判断是否被翻开
     check(row+1,col+1);
       }
     }
}
}

}
public void keyPressed(int n)
{if(n==-6)
{gameStart.midlet.startGame();}
if(n==-7)
{gameStart.midlet.exitGame();}
int k=this.getGameAction(n);
switch(k)
{
  case FullCanvas.UP:
      if(py>=20)  py-=20;
             break;
  case FullCanvas.DOWN:
      if(py<=20*6){py+=20;}
      break;
  case FullCanvas.LEFT:
      if(px>=20) px-=20;
      break;
  case FullCanvas.RIGHT:
        if(px<=20*6)px+=20;
        break;
  case FullCanvas.FIRE:
     int seleRow=py/20;//当前选框的所在行
       int seleCol=px/20;//当前选框的所在列
       check(seleRow,seleCol);//游戏翻开地雷的检测
           //检测过关
  checkWin();
}
this.repaint();
this.serviceRepaints();

}
}

java.lang.NoClassDefFoundError: myCanvas: com/nokia/mid/ui/FullCanvas
此异常为没有打到这个类

事实上我已经导入了这个包，Eclipse的代码检查也没有报错

com/nokia/mid/ui/FullCanvas
是诺基亚的包
wtk怎么会支持呢？
用这个类的话得在诺基亚的模拟器或真机上才能运行

你打包的时候得导入NOKIA的包
WTK有个NOKIA包的补丁的。选择那个模拟器打包运行就不会出错了