flex 、servlet生成验证码方式

flex 、servlet生成验证码方式

-----》flex方式

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<!--简单的flex 验证码-->
<mx:Script>
   <![CDATA[
  
    public function generateRandomCode():String{
     var rndCode = "";
     var number:Number = 0;
     //大写与小写字母
     var base:Array = [65,97];
     for(var i=0; i<4; i++){
      number = Math.floor(Math.random() * 1000);
      //生成0-9
      if(number % 2 == 0)
       number = number % 10 + 48;
      //生成A-Z或a-z
      else
       number = number % 26 + (base[number % 2]);
      rndCode += String.fromCharCode(number);   
     }
     return rndCode;
    }
  
   public function getRandomCode():void{
    rndCode.text = generateRandomCode();
    rndCode2.load("http://localhost:8080/yanzhengma/RandomCodeImage.do");
   }
 
   ]]>
</mx:Script>

<mx:Text x="50" y="50" id="rndCode" creationComplete="getRandomCode()" click="getRandomCode()" fontSize="16"/>

<!--调用java servlet生成的验证码图片-->
<mx:Image x="80" y="80" id="rndCode2"
   source="http://localhost:8080/yanzhengma/RandomCodeImage.do"
   click="getRandomCode()" />

</mx:Application>

-----》java servlet生成
package com.xx;


import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
*TODO 生成随机验证码图片
*Sep 25, 2009
*13:38:50 PM
*Administrator 风清扬ava
*email:[e-mail]
*/
public class RandomCodeImage extends HttpServlet {

     private Font font = new Font("Arial", Font.PLAIN, 18);
     private int width = 60;
     private int height = 20;

     public void init() throws ServletException {}

     public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
       response.reset();
       //响应类型,即MIME类型
       response.setContentType("image/jpeg");
       //response.setContentType("image/gif");

       //不缓存
       response.setHeader("Pragma", "No-cache");
       response.setHeader("Cache-Control", "no-cache");
       response.setDateHeader("Expires", 0);

       BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
       //Graphics g = image.getGraphics();
       Graphics2D g = (Graphics2D)image.getGraphics();
       Random random = new Random();
       g.setColor(getRandColor(200, 250));
       g.fillRect(0, 0, width, height);
       g.setFont(font);
       g.setColor(getRandColor(160, 230));
      
       //生成随机干扰线
       for (int i = 0; i < 255; 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);
       }

       //生成随机字符
       String sRand = "";
       for (int i = 0; i < 4; i++) {
          String rand = String.valueOf(random.nextInt(10));
          byte[] bRand = rand.getBytes();
 
          sRand += rand;
          g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110),
                               20 + random.nextInt(110)));
          g.drawString(rand, 13 * i + 6, 16);
          //g.drawBytes(bRand,0,bRand.length,13 * i + 6, 16);
       }

       //将随机验证码放入session
       request.getSession().setAttribute("rand", sRand);
       //关闭画笔
       g.dispose();
      
       //写出
       ImageIO.write(image, "JPEG", response.getOutputStream());
       //ImageIO.write(image, "PNG", response.getOutputStream());
    }

    /**
     * 生成随机颜色
     * @param fc
     * @param bc
     * @return
     */
    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);
    }

}


摘自：http://hi.baidu.com/%B7%E7%C7%E5%D1%EFjava/blog/item/78756ac9cbf6791c7e3e6f59.html