添加动态验证码

Posted on 2007-07-25 14:26 胡娟阅读(709) 评论(1) 编辑收藏

1.用户信息VO包

package com.hujuan.VO;
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public class UserInfo {
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private String username;
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private String password;
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public String getPassword() {
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return password;
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}
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public void setPassword(String password) {
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this.password = password;
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}
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public String getUsername() {
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return username;
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}
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public void setUsername(String username) {
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this.username = username;
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}
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}

2.验证登录Dao包

package com.hujuan.dao;
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import com.hujuan.VO.UserInfo;
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public class UserInfoDao {
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public boolean checklogin(UserInfo userinfo){
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System.out.println(userinfo.getUsername());
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System.out.println(userinfo.getUsername());
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if("hujuan".equals(userinfo.getUsername())&&"123".equals(userinfo.getPassword())){
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return true;
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}return false;
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}
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}

3.生产随机码验证servlet

package com.hujuan.servlet;
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import java.awt.Graphics2D;
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import java.awt.image.BufferedImage;
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import java.io.IOException;
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import java.util.Random;
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import java.awt.Color;
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import java.awt.Font;
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import javax.imageio.ImageIO;
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import javax.servlet.ServletException;
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import javax.servlet.ServletOutputStream;
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import javax.servlet.http.HttpServlet;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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import javax.servlet.http.HttpSession;
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public class RandomCodeServler extends HttpServlet {
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private int width = 60; //验证图片的宽度
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private int height = 20; //验证图片的高度
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@Override
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protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
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BufferedImage buffImg = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
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Graphics2D g = buffImg.createGraphics();
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//创建一个随机数生产器类
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Random random = new Random();
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g.setColor(Color.WHITE);
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g.fillRect(0, 0, width, height);
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//创建字体，字体的大小应该根据图片的高度来定
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Font font = new Font("123123",Font.PLAIN,18);
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//设置字体
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g.setFont(font);
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//画边框
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g.setColor(Color.BLACK);
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g.drawRect(0, 0, width-1,height-1);
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//随机生产100条干扰线，使图像中的验证吗不易被其他程序探测到
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g.setColor(Color.GRAY);
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for(int i=0;i<100;i++){
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int x = random.nextInt(width);
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int y = random.nextInt(height);
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int x1 = random.nextInt(12);
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int y1 = random.nextInt(12);
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g.drawLine(x, y, x+x1, y+y1);
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}
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//randomCode 用于保存随机产生的验证码，以便用户登录后进行验证
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StringBuffer randomCode = new StringBuffer();
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int red = 0,green = 0,blue = 0;
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//随机产生4位数字的验证码
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for(int i = 0;i<4;i++){
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//得到随机产生的验证码数字
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String strRand = String.valueOf(random.nextInt(10));
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//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
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red = random.nextInt(110);
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green = random.nextInt(50);
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blue = random.nextInt(50);
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//用随机产生的颜色将验证码绘制到图像中
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g.setColor(new Color(red,green,blue));
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g.drawString(strRand, 13*i+6, 16);
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//将产生的四个随机数组合在一起
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randomCode.append(strRand);
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}
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//将四位数字的验证码保存到session中
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HttpSession session = req.getSession();
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session.setAttribute("randomCode", randomCode.toString());
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//禁止图像缓存
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// resp.setHeader("Pragma", "no-cache");
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// resp.setHeader("Cache-Control", "no-cache");
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// resp.setDateHeader("Expires", 0);
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// resp.setContentType("image/jpeg");
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//将图像输出到servlet输出流中
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ServletOutputStream out = resp.getOutputStream();
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ImageIO.write(buffImg,"jpeg",out);
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out.close();
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}
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}
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4.验证登录的servlet

package com.hujuan.servlet;
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import java.io.IOException;
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import java.io.PrintWriter;
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import javax.servlet.ServletException;
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import javax.servlet.http.HttpServlet;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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import javax.servlet.http.HttpSession;
10

import com.hujuan.VO.UserInfo;
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import com.hujuan.dao.UserInfoDao;
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public class LoginCheckServlet extends HttpServlet {
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public void doPost(HttpServletRequest request, HttpServletResponse response)
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throws ServletException, IOException {
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//request.setCharacterEncoding("gb2312");
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response.setCharacterEncoding("gb2312");
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response.setContentType("text/html; charset = gb2312");
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PrintWriter out = response.getWriter();
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HttpSession session = request.getSession();
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String randomCode =(String)session.getAttribute("randomCode");
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if(null == randomCode){
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response.sendRedirect("index.jsp");
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return;
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}
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String reqRandom = request.getParameter("randomcode");//meiyou huode
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UserInfo userinfo = new UserInfo();
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String name = request.getParameter("username");
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String password = request.getParameter("password");
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userinfo.setUsername(name);
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userinfo.setPassword(password);
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// System.out.println(reqRandom);
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// System.out.println(randomCode);
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// System.out.println(name);
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// System.out.println(password);
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if(randomCode.equals(reqRandom)){
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UserInfoDao userdao = new UserInfoDao();
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if(userdao.checklogin(userinfo)){
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response.sendRedirect("succ.jsp");
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}else{
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out.println("请检查用户名和密码");
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}
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}else{
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out.println("请检查验证码");
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}
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}
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}
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5.登录页面

<%@ page language="java" import="java.util.*"
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contentType="text/html; charset=gb2312"%>
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<%
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String path = request.getContextPath();
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String basePath = request.getScheme() + "://"
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+ request.getServerName() + ":" + request.getServerPort()
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+ path + "/";
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%>
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<base href="<%=basePath%>">
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<title>My JSP 'Login.jsp' starting page</title>
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<!--
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-->
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<!--
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.text {
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font-family: "宋体";
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font-size: 12px;
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font-style: normal;
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line-height: 25px;
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font-weight: normal;
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font-variant: normal;
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color: #000000;
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}
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-->
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</style>
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</head>
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<body>
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<form method="post" name="login" action="LoginCheckServlet">
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<p> 
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</p>
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<table width="40%" border="0" align="center">
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<tbody>
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<tr>
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<td width="22%" align="right" class="text"> 用户名 </td>
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<td width="37%"><input name="username" type="text" size="20">
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<br>
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</td>
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</tr>
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<tr>
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<td align="right" class="text"> 密码 </td>
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<td><input name="password" type="password" size="20" maxlength="16">
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</td>
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</tr>
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<tr>
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<td align="right" class="text"> 验证码 </td>
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<td><input name="randomcode" type="text" size="5" maxlength="4">
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<img src="imgcode"> </td>
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</tr>
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<tr>
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<td align="right"> 
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<input type="submit" value="提交" name="submit"> </td>
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<td align="center"> 
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<input type="reset" value="重置" name="reset"> </td>
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</tr>
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</tbody>
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</table>
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</form>
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</body>
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</html>
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6.成功页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
2

<%
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String path = request.getContextPath();
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String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
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%>
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<base href="<%=basePath%>">
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<title>My JSP 'succ.jsp' starting page</title>
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<!--
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-->
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</head>
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<body>
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This is my JSP page. <br>
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</body>
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</html>
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Feedback

# re: 添加动态验证码 回复 更多评论

2012-05-27 22:04 by mable

我觉得很奇怪，为什么我的验证码总是“62”呢？劳烦给我解释一下servlet绘制的验证码图片是怎么放在登陆页面的啊？ <img src="imgcode">，imgcode从哪里来？

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