随机图片验证码(ajax, struts2)

最新推荐文章于 2016-06-24 20:34:00 发布

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最新推荐文章于 2016-06-24 20:34:00 发布

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分类专栏： ajax Struts JEE 文章标签： struts ajax exception random string redirect

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本文介绍了一个简单的验证码生成及验证流程，包括图片生成工具类、验证图片输出Servlet、校验码验证Servlet等内容。通过这些组件实现了验证码的动态生成，并在用户输入后进行验证，确保了系统的安全性。

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1.图片生成工具类

package abu.csdn.util; import java.awt.*; import java.awt.image.BufferedImage; import java.util.Random; /** * * 生成验证用的图片 * * User: Abu Date: 2009-7-2 Time: 12:04:15 */ public class ImageGenerator { // 随机生成的字符串的长度 private final int stringLength = 5; // 图片的背景色 private final Color bgColor = new Color(240, 240, 150); // 干扰线的宽度 private final int lineWidth = 2; // 干扰线的数量 private final int lineNumber = 200; // 字体大小 private final int fontSize = 22; // 随机字符串的字体 private final Font font = new Font("Arial", Font.BOLD, fontSize); // 随机生成的字符串 private String randString; // 图片宽度 private int width; // 图片高度 private int height; /** * * 缺省构造函数 * */ public ImageGenerator() { this(120, 40); } /** * * 自定义构造函数 * * * @param width : * 图片宽度 * @param height : * 图片高度 */ public ImageGenerator(int width, int height) { this.width = width; this.height = height; } /** * * 产生随机前景色,这里的色调基准为深色调 * * * @return 随机颜色 */ private Color createRandColor() { Random random = new Random(); // 红色 int red = random.nextInt(100); // 绿色 int green = random.nextInt(100); // 蓝色 int blue = random.nextInt(100); return new Color(red, green, blue); } /** * * 根据预定义的字符长度,生成随机字符串,规则是字符为数字与大写字母的混合 * * * @return 生成的随机字符串 */ private void createRandString() { StringBuffer sb = new StringBuffer(); Random random = new Random(); // 如果随机数为1,生成数字,否则生成大写字母 for (int i = 0; i < this.stringLength; i++) { if (random.nextInt(2) == 1) { sb.append((char) (random.nextInt(10) + 48)); } else { sb.append((char) (random.nextInt(26) + 65)); } } this.randString = sb.toString(); } /** * * 获得随机字符串 * * * @return 随机字符串 */ public String getRandString() { return randString; } public BufferedImage createImage() { Random random = new Random(); // 图片为指定宽度和高度的RGB类型图片 BufferedImage image = new BufferedImage(this.width, this.height, BufferedImage.TYPE_INT_BGR); Graphics2D graphics = image.createGraphics(); // 设置矩形颜色 graphics.setColor(this.bgColor); // 绘制矩形 graphics.fillRect(0, 0, this.width, this.height); // 设置边框颜色 graphics.setColor(Color.GREEN); // 绘制边框 graphics.drawRect(0, 0, this.width - 1, this.height - 1); // 绘制干扰线 for (int i = 0; i < this.lineNumber; i++) { // 设置线条的颜色 graphics.setColor(this.createRandColor()); int x = random.nextInt(width - lineWidth - 1) + 1; int y = random.nextInt(height - lineWidth - 1) + 1; int xl = random.nextInt(lineWidth); int yl = random.nextInt(lineWidth); graphics.drawLine(x, y, x + xl, y + yl); } // 产生随机字符串 this.createRandString(); graphics.setFont(this.font); // 将字符数组转化成字符数组 char[] chars = this.getRandString().toCharArray(); for (int i=0; i<chars.length; i++) { graphics.setColor(this.createRandColor()); String letter = new Character(chars[i]).toString(); // 这里调整字符的间距和高度,水平偏差为10,高度偏差为15 graphics.drawString(letter, (random.nextInt(10) + (this.fontSize-5)*(i+1) -5), (random.nextInt(10) + 25)); } // 图片生效 graphics.dispose(); return image; } }

2.验证图片输出Servlet

package abu.csdn.servlet; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import abu.csdn.util.ImageGenerator; /** * * * User: Abu Date: 2009-7-2 Time: 14:30:55 */ public class ImageValidatorServlet extends HttpServlet { ImageGenerator imageGenerator = new ImageGenerator(); @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.reset(); // 设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); response.setContentType("image/gif"); // 生成的图片 BufferedImage image = imageGenerator.createImage(); // 随机字符串 String randString = imageGenerator.getRandString(); HttpSession session = request.getSession(true); session.setAttribute("randString", randString); // Servlet输出流 OutputStream out = response.getOutputStream(); // 将图片写入到输出流中去 ImageIO.write(image, "JPG", out); // 强制刷新 out.flush(); // 关闭输出流 out.close(); } }

3.校验码验证Servlet

package abu.csdn.servlet; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; 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; import abu.csdn.util.ImageGenerator; /** * * * User: Abu Date: 2009-7-2 Time: 14:30:55 */ public class ImageVerifyServlet extends HttpServlet { ImageGenerator imageGenerator = new ImageGenerator(); @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //Servlet输出流 ServletOutputStream out = response.getOutputStream(); String randString = request.getSession(true).getAttribute("randString").toString(); String ucode = request.getParameter("ucode"); if (randString.equalsIgnoreCase(ucode)) { out.println(true); } else { out.println(false); } // 关闭输出流 out.close(); } }

4. 测试验证的JSP页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@ taglib uri="/struts-tags" prefix="s"%> <% String imgUrl = "/index.jsp?rand=" + new java.util.Date().getTime(); %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP 'index.jsp' starting page</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"> <mce:script type="text/javascript" src="js/jquery/jquery-min.js" mce_src="js/jquery/jquery-min.js"></mce:script> <mce:script type="text/javascript"></mce:script> </head> <body> <fieldset> <legend> 用户登录 </legend> <s:form name="loginForm" id="loginForm" action="/user/login.do" method="post" theme="simple"> <table> <tr> <td> 用户名 </td> <td> <s:textfield name="uname" id="uname" maxLength="20" /> </td> <td id="unamemsg"></td> </tr> <tr> <td> 密码 </td> <td> <s:password name="upass" id="upass" maxLength="20"/> </td> <td id="upassmsg"></td> </tr> <tr> <td> 校验码 </td> <td> <s:textfield name="ucode" id="ucode" maxLength="5"/> </td> <td id="ucodemsg"></td> </tr> <tr> <td colspan="2" align="right"> <a href="<%=imgUrl%>"><img src="/imageValidator" mce_src="imageValidator" alt="验证码图片" /> </a> </td> </tr> <tr> <td> <s:submit value="提交" id="submit" /> </td> <td align="center"> <s:reset value="重置" id="reset" /> </td> </tr> </table> </s:form> </fieldset> </body> </html>

5. 登录用的Action

package abu.csdn.action.user; import abu.csdn.util.PageUtil; import abu.csdn.util.PageData; import abu.csdn.bean.User; import java.util.List; import org.apache.struts2.ServletActionContext; /** * * 查找用户的Action * * Created by IntelliJ IDEA. User: Abu Date: 2009-6-30 Time: 17:01:59 To * change this template use File | Settings | File Templates. */ public class ReadUserAction extends AbstractUserAction { // 分页工具 private PageUtil pageUtil; // ================================ Struts.xml配置参数 // 每页记录的条数 private int size = 0; // 分页URL private String url; // ================================ 页面参数 // 当前页码 private int page = 0; // 要删除的用户id private long[] uids; public int getPage() { return page; } public void setPage(int page) { this.page = page; } public PageUtil getPageUtil() { return pageUtil; } public void setPageUtil(PageUtil pageUtil) { this.pageUtil = pageUtil; } public int getSize() { return size; } public void setSize(int size) { this.size = size; } public long[] getUids() { return uids; } public void setUids(long[] uids) { this.uids = uids; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } /** * * 查找用户 * * * @return 处理结果RESULT * @throws Exception : * 业务代码异常 */ public String find() throws Exception { // ================================ 分页数据信息 PageData pageData = new PageData(); pageData.setPage(page); pageData.setSize(size); pageData.setTotalRows(userService.getTotalRows()); pageData.setPageSize(userService.getPageSize(size)); // ================================ 分页工具信息 pageUtil.setPageData(pageData); pageUtil.setUrl(url); List<User> list = userService.findByPage(page, size); ServletActionContext.getRequest().setAttribute("list", list); ServletActionContext.getRequest().setAttribute("html", pageUtil.getHtml()); return SUCCESS; } /** * * 根据ID查找用户 * * * @return 处理结果RESULT * @throws Exception : * 业务代码异常 */ public String findById() throws Exception { User entity = userService.findById(uid); if (entity != null) { // 将找到的用户保存在Request中 ServletActionContext.getRequest().setAttribute("entity", entity); return SUCCESS; } else { return ERROR; } } /** * * 用户登录 * * * @return 处理结果RESULT * @throws Exception : * 业务代码异常 */ public String login() throws Exception { // 验证用户,如果成功则返回用户实例,否则返回null User hasLoginedUser = userService.login(uname, upass); if (hasLoginedUser == null) { return LOGIN; } else { // 将已登录用户保存到Session中去 ServletActionContext.getRequest().getSession().setAttribute("user", hasLoginedUser); return SUCCESS; } } }

6.struts.xml配置

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd"> <struts> <package name="user" extends="struts-default" namespace="/user">  <action name="register" class="CreateUserAction" method="register"> <result name="success" type="redirect"> /user/find.do?page=1 </result> <result name="input">/user/register.jsp</result> </action>  <action name="find" class="ReadUserAction" method="find"> <result name="success">/user/index.jsp</result> <result name="input">/user/find.do</result>  <param name="size">10</param>  <param name="url">/user/find.do?page=</param> </action>  <action name="findById" class="ReadUserAction" method="findById"> <result name="success">/user/modify.jsp</result> <result name="error">/user/find.do</result> </action>  <action name="login" class="ReadUserAction" method="login"> <result name="success" type="redirect"> /user/find.do?page=1 </result> <result name="login">/user/register.jsp</result> </action>  <action name="remove" class="DeleteUserAction" method="remove"> <result name="success" type="redirect"> /user/find.do?page=1 </result> <result name="error">/index.jsp</result> </action>  <action name="modify" class="UpdateUserAction" method="modify"> <result name="success" type="redirect"> /user/find.do?page=1 </result> <result name="input">/user/modify.jsp</result> </action> </package> </struts>

7.效果演示

(1)验证成功

验证成功