private static final String AUTH_CODE = "0123456789";
    
    public static String getCheckCode()
    {
        StringBuilder sb = new StringBuilder();
        for(int i = 0;i<4;i++)
        {
            int index = new Random().nextInt(AUTH_CODE.length());
            sb.append(AUTH_CODE.charAt(index));
        }
        return sb.toString();
    }

------解决方案--------------------
1、如下是产生验证码的class，你只需要小小改一下，排除1,0,o,O,l,L,Z,2,9,g等。
Java code


import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

//定义类

public class VerifyCode {
    static Random r = new Random();
    static String ssource =  "0123456789";
    static char[] src = ssource.toCharArray();
    
    
    //产生随机字符串
    
    private static String randString (int length){
        char[] buf = new char[length];
        int rnd;
        for(int i=0;i<length;i++){
            rnd = Math.abs(r.nextInt()) % src.length;
            
            buf[i] = src[rnd];
        }
        return new String(buf);
    }
    
    //调用该方法，产生随机字符串,
    //参数i: 为字符串的长度
    public String runVerifyCode(int i){
        String VerifyCode = randString(i);
        return VerifyCode;
    }
    
    
    //给定范围获得随机颜色
    public Color getRandColor(int fc,int bc)
    {
       Random random = new Random();
       if(fc>255) fc=255;
       if(bc>255) bc=255;
       int r=fc+random.nextInt(bc-fc);
       int g=fc+random.nextInt(bc-fc);
       int b=fc+random.nextInt(bc-fc);
       return new Color(r,g,b);
       }
  
      //调用该方法将得到的验证码生成图象
      //sCode:传递验证码 w:图象宽度 h:图象高度
      public BufferedImage CreateImage(String sCode)
      {
          try{    
              //字符的字体
            Font CodeFont = new Font("Arial Black",Font.PLAIN,16);
            int iLength = sCode.length();                    //得到验证码长度
            int width=22*iLength, height=20;                //图象宽度与高度
            int CharWidth = (int)(width-24)/iLength;        //字符距左边宽度
            int CharHeight = 16;                            //字符距上边高度
            
            // 在内存中创建图象
            BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
            
            // 获取图形上下文
            Graphics g = image.getGraphics();
            
            //生成随机类
            Random random = new Random();
            
            // 设定背景色
            g.setColor(getRandColor(200,240));
            g.fillRect(0, 0, width, height);
            
            //设定字体
            g.setFont(CodeFont);
            
            //画随机颜色的边框
            g.setColor(getRandColor(10,50));
            g.drawRect(0,0,width-1,height-1);
            
            // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
            g.setColor(getRandColor(160,200));
            for (int i=0;i<155;i++)
            {
                  int x = random.nextInt(width);
                  int y = random.nextInt(height);
                  int xl = random.nextInt(12);
                  int yl = random.nextInt(12);
                  g.drawLine(x,y,x+xl,y+yl);
            }
            
    
            for (int i=0;i<iLength;i++)
            {
                String rand = sCode.substring(i,i+1); 
                // 将认证码显示到图象中
                g.setColor(new Color(20+random.nextInt(60),20+random.nextInt(120),20+random.nextInt(180)));
                g.drawString(rand,CharWidth*i+14,CharHeight);
            }
            // 图象生效
            g.dispose();
            return image;
        }catch(Exception e){
            //e.printStackTrace();    
            //System.out.println(e.getMessage());
            }
        return null;
    }
    
    //测试
    public static void main(String[] args){    
            //VerifyCode vc = new VerifyCode();
            //String s1 = vc.runVerifyCode(4);
            //Fun.DreamNewsTitle;System.out.println(s1);    
            //Image im = vc.CreateImage(s1);
            //Graphics g = im.getGraphics();
            //g.drawImage(im,20,20,this);
            //g.drawString(s1,20,20);
            
    }    
}