Java生成验证码（二）使用Kaptcha组件生成图片验证码

来源：互联网发布：ubuntu卸载nvidia驱动编辑：程序博客网时间：2024/06/07 00:14

上篇，Java生成验证码，http://blog.csdn.net/hanxueyu666/article/details/52016740 是用原生态的代码来生成图片验证码的，今天我又学习了一个新的方法，可以生成各种样式的图片验证码，体验效果更好，那就是利用kaptcha组件来实现。

效果图：

1、首先创建web项目，并且引入kaptcha的jar包，jar包可以去官网下载

官网下载jar:http://code.google.com/p/kaptcha/

2、建立jsp页面

<%@ 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><script type="text/javascript">function reloadCode(){var time = new Date().getTime();document.getElementById("kaptchaImage").src = "kaptcha.jpg?"+time;}</script></head><body><form action="Kaptcha" method="post"> <a href="javascript:reloadCode();"><img src="kaptcha.jpg" id="kaptchaImage"/></a><input type="text"name="kaptcha" value="" /> <input type="submit" name="submit"value="submit" /></form></body></html>

3、建立自己的servlet，用来验证用户输入的验证码和图片上的验证码是否一致，并输出结果，一致，输出成功；否则输出失败。

package com.slowly;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class Kaptcha */@WebServlet("/Kaptcha")//注意此处不要删去，删去会出现问题，我也不太清楚，可能是servlet3.0能够自己配置xml的原因吧public class Kaptcha extends HttpServlet {private static final long serialVersionUID = 1L;           /**     * @see HttpServlet#HttpServlet()     */    public Kaptcha() {        super();        // TODO Auto-generated constructor stub    }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {String kaptchaExpected = (String)request.getSession()    .getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);//<span style="font-family: 'Microsoft YaHei', 微软雅黑, Arial, 'Lucida Grande', Tahoma, sans-serif; font-size: 13px; line-height: 24.05px;">KaptchaServlet会把验证码设置到session中，可以这样获取</span>String code = request.getParameter("kaptcha");response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();if(code.equalsIgnoreCase(kaptchaExpected)){out.println("成功！！！");}else{out.println("失败！！！");}out.flush();out.close();}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(request, response);}}

4.配置xml，这里我把常见的kaptcha的xml所需配置的详细配置都列出了

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">  <servlet> <!-- 生成图片的Servlet -->        <servlet-name>KaptchaServlet</servlet-name>        <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>                            <!-- 是否有边框-->        <init-param>             <param-name>kaptcha.border</param-name>             <param-value>no</param-value>         </init-param>             <!-- 字体颜色 -->         <init-param>            <param-name>kaptcha.textproducer.font.color</param-name>             <param-value>red</param-value>         </init-param>         <!-- 图片宽度 -->         <init-param>             <param-name>kaptcha.image.width</param-name>             <param-value>135</param-value>         </init-param>         <!-- 使用哪些字符生成验证码 -->         <init-param>             <param-name>kaptcha.textproducer.char.string</param-name>             <param-value>ACDEFHKPRSTWX345679</param-value>         </init-param>         <!-- 图片高度 -->         <init-param>             <param-name>kaptcha.image.height</param-name>             <param-value>50</param-value>         </init-param>         <!-- 字体大小 -->         <init-param>             <param-name>kaptcha.textproducer.font.size</param-name>             <param-value>43</param-value>         </init-param>         <!-- 干扰线的颜色 -->         <init-param>             <param-name>kaptcha.noise.color</param-name>             <param-value>black</param-value>         </init-param>         <!-- 字符个数 -->         <init-param>             <param-name>kaptcha.textproducer.char.length</param-name>            <param-value>4</param-value>        </init-param>         <!-- 使用哪些字体 -->         <init-param>             <param-name>kaptcha.textproducer.font.names</param-name>             <param-value>Arial</param-value>        </init-param>   </servlet>  <servlet-mapping>    <servlet-name>KaptchaServlet</servlet-name>    <url-pattern>/kaptcha.jpg</url-pattern>  </servlet-mapping>  </web-app>

0 0

Java生成验证码（二） 使用Kaptcha组件生成图片验证码

Java生成验证码（二）使用Kaptcha组件生成图片验证码