验证码相关

public class RandomNumUtil {


      private ByteArrayInputStream image;//图像  
        private String str;//验证码  
          
        private RandomNumUtil(){  
            init();//初始化属性  
        }  
        /*
         * 取得RandomNumUtil实例
         */
        public static RandomNumUtil Instance(){  
            return new RandomNumUtil();  
        }  
        /*
         * 取得验证码图片
         */
        public ByteArrayInputStream getImage(){  
            return this.image;  
        }  
        /*
         * 取得图片的验证码
         */
        public String getString(){  
            return this.str;  
        }  
          
        private void init() {  
            //       在内存中创建图象  
            int width=85, height=20;  
            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(200,250));  
            g.fillRect(0, 0, width, height);  
            //      设定字体  
            g.setFont(new Font("Times New Roman",Font.PLAIN,18));  
            //       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);  
            }  
            //       取随机产生的认证码(6位数字)  
            String sRand="";  
            for (int i=0;i<6;i++){  
                String rand=String.valueOf(random.nextInt(10));  
                sRand+=rand;  
                // 将认证码显示到图象中  
                g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));  
                //      调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成  
                g.drawString(rand,13*i+6,16);   
            }
            //赋值验证码
            this.str=sRand;
           
            //图象生效  
            g.dispose();  
            ByteArrayInputStream input=null;  
            ByteArrayOutputStream output = new ByteArrayOutputStream();  
            try{  
                ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);  
                ImageIO.write(image, "JPEG", imageOut);  
                imageOut.close();  
                input = new ByteArrayInputStream(output.toByteArray());  
            }catch(Exception e){  
                System.out.println("验证码图片产生出现错误："+e.toString());  
            }  
              
            this.image=input;/* 赋值图像 */
        }  
        /*
         * 给定范围获得随机颜色
         */
        private 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);  
       }


}


验证码action类

public class RandomAction extends BasicAction{


     private ByteArrayInputStream inputStream;  
        public String execute() throws Exception{  
            RandomNumUtil rdnu=RandomNumUtil.Instance();  
            this.setInputStream(rdnu.getImage());//取得带有随机字符串的图片  
            ActionContext.getContext().getSession().put("random", rdnu.getString());//取得随机字符串放入HttpSession 
           
            return SUCCESS;  
        }  
        public void setInputStream(ByteArrayInputStream inputStream) {  
            this.inputStream = inputStream;  
        }  
        public ByteArrayInputStream getInputStream() {  
            return inputStream;  
        }
}




用户登录前打验证方法，主要说用于验证验证码的正确与否



    public void validateLoginUser() throws Exception{
       String arandom=(String)(ActionContext.getContext().getSession().get("random"));
       try {
           if(arandom !=null){
              String validateCode=arandom.toString();
              if(rand != null && !rand.equals(validateCode)){
                  this.addFieldError("rand","验证码错误！");
              }
           }
       } catch (Exception e) {
           LOG.error("拉取验证码失败",e);
           throw e;
       }
    }