Servlet实现图形验证码

来源：互联网发布：淘宝宝贝描述模板软件编辑：程序博客网时间：2024/05/29 17:33

1. 开发环境

|-- tomcat7

|-- eclipse

|-- jdk1.7

2. 项目结构

|-- demo

|-- src

|-- asia.hchx.filter

|-- CharacterFilter

|-- LoginFilter

|-- asia.hchx.servlet

|-- LoginServlet

|-- VerifyImage

|-- WebContent

|-- index.jsp

|-- login.jsp

3. 测试步骤

|-- 创建web项目

|-- 配置开发图形验证码Servlet

package asia.phome.servlet;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/verifyCode.do")public class VerifyImage extends HttpServlet {// 产生随即的字体private Font getFont() {Random random = new Random();Font font[] = new Font[5];font[0] = new Font("Ravie", Font.PLAIN, 24);font[1] = new Font("Antique Olive Compact", Font.PLAIN, 24);font[2] = new Font("Forte", Font.PLAIN, 24);font[3] = new Font("Wide Latin", Font.PLAIN, 24);font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, 24);return font[random.nextInt(5)];}protected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// 设置响应头 Content-type类型resp.setContentType("image/jpeg");// 以下三句是用于设置页面不缓存resp.setHeader("Pragma", "No-cache");resp.setHeader("Cache-Control", "No-cache");resp.setDateHeader("Expires", 0);OutputStream os = resp.getOutputStream();int width = 83, height = 30;// 建立指定宽、高和BufferedImage对象BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics(); // 该画笔画在image上Color c = g.getColor(); // 保存当前画笔的颜色，用完画笔后要回复现场g.fillRect(0, 0, width, height);char[] ch = "abcdefghigklmnopqrstuvwxyz".concat("ABCDEFGHIJKLMNOPQRSTUV").concat("WXYZ0123456789").toCharArray(); // 随即产生的字符串// 不包括 i// l(小写L)// o（小写O）// 1（数字1）0(数字0)int length = ch.length; // 随即字符串的长度String sRand = ""; // 保存随即产生的字符串Random random = new Random();for (int i = 0; i < 4; i++) {// 设置字体g.setFont(getFont());// 随即生成0-9的数字String rand = new Character(ch[random.nextInt(length)]).toString();sRand += rand;// 设置随机颜色g.setColor(new Color(random.nextInt(255), random.nextInt(255),random.nextInt(255)));g.drawString(rand, 20 * i + 6, 25);}// 产生随即干扰点for (int i = 0; i < 40; i++) {int x1 = random.nextInt(width);int y1 = random.nextInt(height);g.drawOval(x1, y1, 2, 2);}g.setColor(c); // 将画笔的颜色再设置回去g.dispose();// 将验证码记录到sessionreq.getSession().setAttribute("safecode", sRand);// 输出图像到页面ImageIO.write(image, "JPEG", os);}protected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doGet(req, resp);}}

|-- 登录页面配置图形验证码login.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"><title>Insert title here</title></head><body><form method="post" action="${pageContext.request.contextPath }/login.do">username:<input type="text" name="username"/><br />password:<input type="text" name="password"/><br /><!-- img中的src属性中，配置VerifyImage的请求 -->verify code:<img src="${pageContext.request.contextPath }/verifyCode.do"/><input type="text" name="verifyCode"/><br /><input type="checkbox" value="1" name="rememberMe"/>记住密码<br /><input type="submit" value="登陆"/></form></body></html>

|-- 登录的Servlet配置——LoginServlet

package asia.phome.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.log4j.Logger;@WebServlet("/login.do")public class LoginServlet extends HttpServlet{Logger log = Logger.getLogger(LoginServlet.class);@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {log.debug("开始执行doGet方法");this.doPost(req, resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {log.debug("开始执行doPost方法");req.setCharacterEncoding("UTF-8");resp.setContentType("text/html;charset=UTF-8");log.debug("开始接收参数");String username = req.getParameter("username");String password = req.getParameter("password");String safeCode = req.getParameter("verifyCode");log.debug("接收到参数:username =" + username + ";password=" + password+ ";safecode=" + safeCode);// 获取验证码String sc = (String) req.getSession().getAttribute("safecode");log.warn("服务器中的验证码：" + sc);if (!sc.equalsIgnoreCase(safeCode)) {log.warn("验证码输入有误!");resp.sendRedirect("login.jsp");return;}String isRe = req.getParameter("rememberMe");log.debug("是否记住密码：" + isRe);if ("1".equals(isRe)) {/* *  记住密码 *  在客户端的Cookie中，写入一个字符串标识 */// 创建cookielog.debug("创建Cookie");Cookie cookie = new Cookie("rememberMe", username);// 将cookie绑定到响应中log.debug("绑定Cookie到响应中");resp.addCookie(cookie);}if ("admin".equals(username)&& "admin".equals(password)) {log.debug("登录成功，跳转到Index.jsp页面");req.getSession().setAttribute("loginuser", username);resp.sendRedirect("index.jsp");} else {log.debug("登录失败，跳转到error.jsp页面");resp.sendRedirect("error.jsp");}}}

|-- 测试

运行项目，页面上出现如下图形验证码

0 0