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.p_w_picpath.BufferedImage;
- import java.io.IOException;
- import java.util.Random;
- import javax.p_w_picpathio.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>