JAVA 验证码解决方案汇总

（方案一）

import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics2D;  
import java.awt.image.BufferedImage;  
import java.util.Random;  
 
import javax.imageio.ImageIO;  
import javax.servlet.ServletException;  
import javax.servlet.ServletOutputStream;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
 
/**
* Package name : com.skcc.sample.action
* File name : VerifyCodeServlet.java
* Author : Administrator
* Date : 2008-9-4
* Description : VerifyCodeServlet
*/
public class VerifyCodeServlet extends HttpServlet {  
 
   
    /**
    * 验证码图片的宽度。
    */
    private int width = 60;  
   
    /**
    *  验证码图片的高度。
    */
    private int height = 20;  
 
 
    /**
    * 验证码字符个数
    */
    private int codeCount = 4;  
 
    /**
    * xx
    */
    private int xx = 0;  
 
    /**
    * 字体高度  
    */
    private int fontHeight;  
 
    /**
    * codeY
    */
    private int codeY;  
 
    /**
    * codeSequence
    */
    char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',  
            'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',  
            'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };  
 
    /** 
     * 初始化验证图片属性 
     */ 
    public void init() throws ServletException {  
        // 从web.xml中获取初始信息  
        // 宽度  
        String strWidth = this.getInitParameter("width");  
        // 高度  
        String strHeight = this.getInitParameter("height");  
        // 字符个数  
        String strCodeCount = this.getInitParameter("codeCount");  
 
        // 将配置的信息转换成数值  
        try {  
            if (strWidth != null && strWidth.length() != 0) {  
                width = Integer.parseInt(strWidth);  
            }  
            if (strHeight != null && strHeight.length() != 0) {  
                height = Integer.parseInt(strHeight);  
            }  
            if (strCodeCount != null && strCodeCount.length() != 0) {  
                codeCount = Integer.parseInt(strCodeCount);  
            }  
        } catch (NumberFormatException e) {
         e.printStackTrace();
        }  
 
        xx = width / (codeCount + 1);  
        fontHeight = height - 2;  
        codeY = height - 4;  
 
    }  
 
    /**
    * @param req
    * @param resp
    * @throws ServletException
    * @throws java.io.IOException
    */
    protected void service(HttpServletRequest req, HttpServletResponse resp)  
            throws ServletException, java.io.IOException {  
 
        // 定义图像buffer  
        BufferedImage buffImg = new BufferedImage(width, height,  
                BufferedImage.TYPE_INT_RGB);  
        Graphics2D gd = buffImg.createGraphics();  
 
        // 创建一个随机数生成器类  
        Random random = new Random();  
 
        // 将图像填充为白色  
        gd.setColor(Color.WHITE);  
        gd.fillRect(0, 0, width, height);  
 
        // 创建字体，字体的大小应该根据图片的高度来定。  
        Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);  
        // 设置字体。  
        gd.setFont(font);  
 
        // 画边框。  
        gd.setColor(Color.BLACK);  
        gd.drawRect(0, 0, width - 1, height - 1);  
 
        // 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。  
        gd.setColor(Color.BLACK);  
        for (int i = 0; i < 160; i++) {  
            int x = random.nextInt(width);  
            int y = random.nextInt(height);  
            int xl = random.nextInt(12);  
            int yl = random.nextInt(12);  
            gd.drawLine(x, y, x + xl, y + yl);  
        }  
 
        // randomCode用于保存随机产生的验证码，以便用户登录后进行验证。  
        StringBuffer randomCode = new StringBuffer();  
        int red = 0, green = 0, blue = 0;  
 
        // 随机产生codeCount数字的验证码。  
        for (int i = 0; i < codeCount; i++) {  
            // 得到随机产生的验证码数字。  
            String strRand = String.valueOf(codeSequence[random.nextInt(36)]);  
            // 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。  
            red = random.nextInt(255);  
            green = random.nextInt(255);  
            blue = random.nextInt(255);  
 
            // 用随机产生的颜色将验证码绘制到图像中。  
            gd.setColor(new Color(red, green, blue));  
            gd.drawString(strRand, (i + 1) * xx, codeY);  
 
            // 将产生的四个随机数组合在一起。  
            randomCode.append(strRand);  
        }  
        // 将四位数字的验证码保存到Session中。  
        HttpSession session = req.getSession();  
        session.setAttribute("validateCode", randomCode.toString());  
 
        // 禁止图像缓存。  
        resp.setHeader("Pragma", "no-cache");  
        resp.setHeader("Cache-Control", "no-cache");  
        resp.setDateHeader("Expires", 0);  
 
        resp.setContentType("image/jpeg");  
 
        // 将图像输出到Servlet输出流中。  
        ServletOutputStream sos = resp.getOutputStream();  
        ImageIO.write(buffImg, "jpeg", sos);  
        sos.close();  
    }  
 
} 

产生结果servlet

import java.io.IOException;  
import java.io.PrintWriter;  
 
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
 
/**
* Package name : com.skcc.sample.action
* File name : ResultServlet.java
* Author : Administrator
* Date : 2008-9-4
* Description : ResultServlet
*/
public class ResultServlet extends HttpServlet {  
 
    /** 
     * The doGet method of the servlet. <br> 
     * 
     * This method is called when a form has its tag value method equals to get. 
     *  
     * @param request the request send by the client to the server 
     * @param response the response send by the server to the client 
     * @throws ServletException if an error occurred 
     * @throws IOException if an error occurred 
     */ 
    public void doGet(HttpServletRequest request, HttpServletResponse response)  
            throws ServletException, IOException {  
 
        doPost(request, response);  
    }  
 
    /** 
     * The doPost method of the servlet. <br> 
     * 
     * This method is called when a form has its tag value method equals to post. 
     *  
     * @param request the request send by the client to the server 
     * @param response the response send by the server to the client 
     * @throws ServletException if an error occurred 
     * @throws IOException if an error occurred 
     */ 
    public void doPost(HttpServletRequest request, HttpServletResponse response)  
            throws ServletException, IOException {  
 
        response.setContentType("text/html;charset=utf-8");  
        String validateC = (String) request.getSession().getAttribute("validateCode");  
        String veryCode = request.getParameter("c");  
        PrintWriter out = response.getWriter();  
        if(veryCode==null||"".equals(veryCode)){  
            out.println("验证码为空");  
        }else{  
            if(validateC.equals(veryCode)){  
                out.println("验证码正确");  
            }else{  
                out.println("验证码错误");  
            }  
        }  
        out.flush();  
        out.close();  
    }  
 
} 
js 文件

function changeImg(){  
    var imgSrc = $("#imgObj");  
    var src = imgSrc.attr("src");  
    imgSrc.attr("src",chgurl(/blog/src));  
}  
//时间戳  
//为了使每次生成图片不一致，即不让浏览器读缓存，所以需要加上时间戳  
function chgurl(/blog/url){  
    var timestamp = (new Date()).valueOf();  
    url = url.substring(0,17);  
    if((url.indexOf("&")>=0)){  
        url = url + "×tamp=" + timestamp;  
    }else{  
        url = url + "?timestamp=" + timestamp;  
    }  
    return url;  
}  
 
function isRightCode(){  
    var code = $("#veryCode").attr("value");  
    code = "c=" + code;  
    $.ajax({  
        type:"POST",  
        url:"resultServlet",  
        data:code,  
        success:callback  
    });  
}  
 
function callback(data){  
    $("#info").html(data);  
} 
页面 verifyCode.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" 
    pageEncoding="UTF-8"%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html> 
    <head> 
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 
        <script type="text/javascript" src="/blog/js/verifyCode.js"></script> 
        <script type="text/javascript" src="/blog/js/jquery.js"></script> 
        <title>test verify code</title> 
    </head> 
    <body> 
        <input id="veryCode" name="veryCode" type="text"/> 
        <img id="imgObj" alt="" src="/blog/verifyCodeServlet"/> 
        <a href="#" onclick="changeImg()">换一张</a> 
        <input type="button" value="验证" onclick="isRightCode()"/> 
        <div id="info"></div> 
    </body> 
</html>

最后记得配好web.xml

 <servlet>
     <servlet-name>VerifyCodeServlet</servlet-name>
     <servlet-class>com.sample.action.VerifyCodeServlet</servlet-class>
    </servlet>
    <servlet>
     <servlet-name>ResultServlet</servlet-name>
     <servlet-class>com.sample.action.ResultServlet</servlet-class>
    </servlet>
    <servlet-mapping>
     <servlet-name>VerifyCodeServlet</servlet-name>
     <url-pattern>/verifyCodeServlet</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
     <servlet-name>ResultServlet</servlet-name>
     <url-pattern>/resultServlet</url-pattern>
    </servlet-mapping>

 

 

（方案二）

1.ImageServlet类的实现：

package com.mobile.control;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

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;

public class ImageServlet extends HttpServlet {

       public void doGet(HttpServletRequest request, HttpServletResponse response)

                     throws ServletException, IOException {

              this.doPost(request, response);

       }

       // 生成数字和字母的验证码

       public void doPost(HttpServletRequest request, HttpServletResponse response)

                     throws ServletException, IOException {

              BufferedImage img = new BufferedImage(68, 22,

                            BufferedImage.TYPE_INT_RGB);

              // 得到该图片的绘图对象

              Graphics g = img.getGraphics();

              Random r = new Random();

              Color c = new Color(200, 150, 255);

              g.setColor(c);

              // 填充整个图片的颜色

              g.fillRect(0, 0, 68, 22);

              // 向图片中输出数字和字母

              StringBuffer sb = new StringBuffer();

              char[] ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();

              int index, len = ch.length;

              for (int i = 0; i < 4; i ++) {

                     index = r.nextInt(len);

                     g.setColor(new Color(r.nextInt(88), r.nextInt(188), r.nextInt

(255)));

                     g.setFont(new Font("Arial", Font.BOLD | Font.ITALIC, 22));// 输出的

字体和大小                 

                     g.drawString("" + ch[index], (i * 15) + 3, 18);//写什么数字，在图片

的什么位置画

                     sb.append(ch[index]);

              }

              request.getSession().setAttribute("piccode", sb.toString());

              ImageIO.write(img, "JPG", response.getOutputStream());

       }    

}

2.web.xml中的配置

       <servlet>

              <servlet-name>ImageServlet</servlet-name>

              <servlet-class>com.mobile.control.ImageServlet</servlet-class>

       </servlet>

       <servlet-mapping>

              <servlet-name>ImageServlet</servlet-name>

              <url-pattern>/servlet/ImageServlet</url-pattern>

       </servlet-mapping>

3.页面源程序

<%@ page contentType="text/html; charset=utf-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

       <head>

              <title>系统登录</title>

              <meta http-equiv="pragma" content="no-cache">

              <meta http-equiv="cache-control" content="no-cache">

              <meta http-equiv="expires" content="0">

              <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

              <meta http-equiv="description" content="This is my page">            

             

              <link href="<%=request.getContextPath()%>/jsp/style/stylet.css"

                     rel="stylesheet" type="text/css">  

              <mce:script type="text/javascript"><!--

                     // 重载验证码

                     function reloadVerifyCode(){

                            var timenow = new Date().getTime();                       

                            document.getElementById("safecode").src="<%

=request.getContextPath()%>/servlet/ImageServlet?d="+timenow;

                     }

             

             

// --></mce:script>

       </head>

      

       <body>

              <div id="box1">

                     <div id="tab_box">

                            <form action="<%=request.getContextPath() %

>/servlet/LoginServlet" method="post" name="login">

                                   <span class="denglu_font_title">欢迎登录</span>

                                   <br />

                                   <br />

                                   <label for="userid" class="yonghuming_font">

                                          用户：

                                   </label>

                                   <input name="userid" type="text" id="userid"

accesskey="n"

                                          tabindex="1"

                                          style="font-family: '宋体'; font-size: 12px;

color: #575757" />

                                   <br />

                                   <br />

                                   <label for="passwd" class="yonghuming_font">

                                          密码：

                                   </label>

                                   <input name="passwd" type="password" id="passwd"

tabindex="2"

                                          style="font-family: '宋体'; font-size: 12px;

color: #575757" />

                                   <br />

                                   <br />                                              

                                   <label for="verifyCode" class="yonghuming_font">

                                          验证码：

                                   </label>

                                   <input type="text" id="verifyCode" name="verifyCode"

size="6" />

                                   <img alt="验证码" id="safecode" src="<%

=request.getContextPath()%>/servlet/ImageServlet">

                                   <a href="javascript:reloadVerifyCode();"

mce_href="javascript:reloadVerifyCode();">看不清楚</a>

                                   <input name="denglu_tijiao" type="submit"

id="denglu_tijiao"

                                          tabindex="3" value="确认" />

                                   <input name="denglu_chongzi" type="reset"

id="denglu_reset"

                                          tabindex="4" value="重置" />

                                   <input type="hidden" name="flag" value="logon">

                            </form>

                            <font color='red'></font>

                     </div>

              </div>

       </body>

</html>

 

（方案三）

JAVA验证码带中文

该类包含数字验证码和中文汉字验证码

creatImage() 方法为数字验证码，效果：
creatImageGB() 方法为汉字验证码，效果：

Image.java 源代码

package you package;

import java.awt.*;

import java.awt.image.*;

import java.util.*;

/**

 * @author from Internet

 * @last update:2006-05-23 Ychon

 *

 */

public class Image {

 public String sRand = "";

 public String sgbRand = "";

 public Color getRandColor(int fc, int bc) { //给定范围获得随机颜色 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);

 }

 public BufferedImage creatImage() {

// 在内存中创建图象

 int width = 60, 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(100, 250));

 g.fillRect(0, 0, width, height);

//设定字体

 g.setFont(new Font("Comic Sans MS", Font.PLAIN, 18));

//画边框

//g.setColor(new Color());

//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);

 }

// 取随机产生的认证码(4位数字)

//String rand = request.getParameter("rand");

//rand = rand.substring(0,rand.indexOf("."));

 for (int i = 0; i < 4; 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);

 }

// 图象生效

 g.dispose();

 return image;

 }

 public BufferedImage creatImageGB() {

// 在内存中创建图象

 int width = 170, height = 28;

 //设置备选汉字，剔除一些不雅的汉字

 String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6"

//备选汉字的长度

 ;

 int length = base.length();

//创建内存图像

 BufferedImage image = new BufferedImage(width, height,

 BufferedImage.TYPE_INT_RGB);

// 获取图形上下文

 Graphics g = image.getGraphics();

//创建随机类的实例

 Random random = new Random();

// 设定图像背景色(因为是做背景，所以偏淡)

 g.setColor(getRandColor(200, 250));

 g.fillRect(0, 0, width, height);

//备选字体

 String[] fontTypes = {"\u5b8b\u4f53", "\u65b0\u5b8b\u4f53",

 "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66"};

 int fontTypesLength = fontTypes.length;

//在图片背景上增加噪点

 g.setColor(getRandColor(160, 200));

 g.setFont(new Font("Comic Sans MS", Font.PLAIN, 14));

 for (int i = 0; i < 6; i++) {

 g.drawString("*********************************************", 0,

 5 * (i + 2));

 }

//取随机产生的认证码(6个汉字)

//保存生成的汉字字符串

 for (int i = 0; i < 6; i++) {

 int start = random.nextInt(length);

 String rand = base.substring(start, start + 1);

 sgbRand += rand;

//设置字体的颜色

 g.setColor(getRandColor(10, 150));

//设置字体

 g.setFont(new Font(fontTypes[random.nextInt(fontTypesLength)],

 Font.BOLD, 18 + random.nextInt(6)));

//将此汉字画到图片上

 g.drawString(rand, 24 * i + 10 + random.nextInt(8), 24);

 }

 g.dispose();

 return image;

 }

 public static void main(String[] args) {

 Image image = new Image();

 }

}

输出显示：

<%@ page import="javax.imageio.*,com.Image" %>

<%

Image image = new Image();

//设置页面不缓存

response.setHeader("Pragma","No-cache");

response.setHeader("Cache-Control","no-cache");

response.setDateHeader("Expires", 0);

// 输出图象到页面

out.clear();

//ImageIO.write(image.creatImage(), "JPEG", response.getOutputStream()); //数字

ImageIO.write(image.creatImageGB(), "JPEG", response.getOutputStream()); //汉字

// 将认证码存入SESSION

//session.setAttribute("imgCode",image.sRand); //数字

session.setAttribute("imgCode",image.sgbRand);//汉字

%>