springMVC使用kaptcha实现登录验证码

1.spring 配置文件 applicationContext.xml

<!-- 登陆时验证码的配置 --><bean id="captchaProducer" class="com.google.code.kaptcha.impl.DefaultKaptcha"><property name="config"><bean class="com.google.code.kaptcha.util.Config"><!--通过构造函数注入属性值 --><constructor-arg type="java.util.Properties"><props><!-- 验证码宽度 --><prop key="kaptcha.image.width">115</prop><!-- 验证码高度 --><prop key="kaptcha.image.height">46</prop><!-- 生成验证码内容范围 --><prop key="kaptcha.textproducer.char.string">abcde012345678gfynmnpwx</prop><!-- 验证码个数 --><prop key="kaptcha.textproducer.char.length">5</prop><!-- 是否有边框 --><prop key="kaptcha.border">no</prop><!-- 验证码字体颜色 --><prop key="kaptcha.textproducer.font.color">white</prop><!-- 验证码字体大小 --><prop key="kaptcha.textproducer.font.size">25</prop><!-- 验证码所属字体样式 --><prop key="kaptcha.textproducer.font.names">Arial, Courier</prop><prop key="kaptcha.background.clear.from">104,183,26</prop><prop key="kaptcha.background.clear.to">104,183,26</prop><prop key="kaptcha.obscurificator.impl">com.google.code.kaptcha.impl.ShadowGimpy</prop><prop key="kaptcha.noise.impl">com.google.code.kaptcha.impl.NoNoise</prop><!-- 干扰线颜色 --><prop key="kaptcha.noise.color">red</prop><!-- 验证码文本字符间距 --><prop key="kaptcha.textproducer.char.space">1</prop></props></constructor-arg></bean></property></bean>

2.Controller的实现

package com.nis.web.controller;import java.awt.image.BufferedImage;import java.io.IOException;import javax.imageio.ImageIO;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import com.google.code.kaptcha.Constants;import com.google.code.kaptcha.Producer;@Controllerpublic class CaptchaProducerController {@Autowiredprivate Producer captchaProducer;@RequestMapping("captcha-image")public ModelAndView handleRequest(HttpServletRequest request,HttpServletResponse response) throws IOException{  // Set to expire far in the past.        response.setDateHeader("Expires", 0);        // Set standard HTTP/1.1 no-cache headers.        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");        // Set IE extended HTTP/1.1 no-cache headers (use addHeader).        response.addHeader("Cache-Control", "post-check=0, pre-check=0");        // Set standard HTTP/1.0 no-cache header.        response.setHeader("Pragma", "no-cache");                  // return a jpeg        response.setContentType("image/jpeg");        // create the text for the image        String capText = captchaProducer.createText();                // store the text in the session        request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, capText.toUpperCase());        // create the image with the text        BufferedImage bi = captchaProducer.createImage(capText);        ServletOutputStream out = response.getOutputStream();                // write the data out        ImageIO.write(bi, "jpg", out);        try        {                out.flush();        }        finally        {                out.close();        }return null;}}

3.JSP页面代码

<form id="loginForm" class="form-signin" action="${pageContext.request.contextPath }/login" method="post">    <div class="loginbox loginbox2">    <ul>    <li><input id="username" name="username" type="text" class="loginuser required" value="${username}" placeholder="请填写登录账号"/></li>    <li><input type="password"  class="loginpwd required"  id="password" name="password" placeholder="请填写登录密码"/></li>  <c:if test="${not empty isValidateCodeLogin and isValidateCodeLogin==true}">             <li class="yzm">    <span><input id="captcha" name="captcha" class="required" type="text" placeholder="验证码"/></span><cite><img alt="未获取验证码" src="${pageContext.request.contextPath}/captcha-image" id="captacha_image" class="mid"/></cite>     </li>              </c:if>        <li><input  type="submit" class="loginbtn" value="登录"/>    <label><input  id="rememberMe" name="rememberMe" ${rememberMe ? 'checked' : ''} type="checkbox" />记住我（公共场所慎用）</label>    </li>    </ul>         <div class="bottom"><div id="messageBox" class="alert alert-error ${empty message ? 'hide' : ''}"><label id="loginError" class="error">${message}</label></div></div>        </div>    </form>

使用Jquery.validate方法来调用controller的方法进行验证

$("#loginForm").validate({    rules: {    username: { required: true},                        password: { required: true},                        captcha: {remote: "${pageContext.request.contextPath}/validateCode"}//动态增加删除验证规则，访问validateCode进行验证    },    messages: {    username: {required: "请填写用户名..."},password: {required: "请填写密码..."},    captcha: {remote: "验证码不正确...", required: "请填写验证码..."}    },    errorLabelContainer: "#messageBox",//显示错误信息的容器    errorPlacement: function(error, element) {//显示位置及添加方式    error.appendTo($("#loginError").parent());    }     });

4.java验证代码

@RequestMapping(value="/validateCode")public void validateCode(HttpServletRequest request, HttpServletResponse response,String captcha) {renderString(response, UserUtils.validateCodeIsValid(captcha));}/** * 验证码是否合法 * @param validateCode * @return */public static boolean validateCodeIsValid(String validateCode) {String code = (String) getSession().getAttribute(Constants.KAPTCHA_SESSION_KEY);return (StringUtil.isBlank(validateCode) || validateCode.toUpperCase().equals(code));}/** * 客户端返回JSON字符串 * @param response * @param object * @return */protected String renderString(HttpServletResponse response, Object object) {return renderString(response, JsonMapper.toJsonString(object), "application/json");}/**     * 客户端返回字符串     * @param response     * @param string     * @return     */    protected String renderString(HttpServletResponse response, String string, String type) {        try {            response.reset();            response.setContentType(type);            response.setCharacterEncoding("utf-8");            response.getWriter().print(string);            return null;        } catch (IOException e) {            return null;        }    }

5.kaptcha可配置项

kaptcha.border  是否有边框  默认为true  我们可以自己设置yes，no  kaptcha.border.color   边框颜色   默认为Color.BLACK  kaptcha.border.thickness  边框粗细度  默认为1  kaptcha.producer.impl   验证码生成器  默认为DefaultKaptcha  kaptcha.textproducer.impl   验证码文本生成器  默认为DefaultTextCreator  kaptcha.textproducer.char.string   验证码文本字符内容范围  默认为abcde2345678gfynmnpwx  kaptcha.textproducer.char.length   验证码文本字符长度  默认为5  kaptcha.textproducer.font.names    验证码文本字体样式  默认为new Font("Arial", 1, fontSize), new Font("Courier", 1, fontSize)  kaptcha.textproducer.font.size   验证码文本字符大小  默认为40  kaptcha.textproducer.font.color  验证码文本字符颜色  默认为Color.BLACK  kaptcha.textproducer.char.space  验证码文本字符间距  默认为2  kaptcha.noise.impl    验证码噪点生成对象  默认为DefaultNoise  kaptcha.noise.color   验证码噪点颜色   默认为Color.BLACK  kaptcha.obscurificator.impl   验证码样式引擎  默认为WaterRipple  kaptcha.word.impl   验证码文本字符渲染   默认为DefaultWordRenderer  kaptcha.background.impl   验证码背景生成器   默认为DefaultBackground  kaptcha.background.clear.from   验证码背景颜色渐进   默认为Color.LIGHT_GRAY  kaptcha.background.clear.to   验证码背景颜色渐进   默认为Color.WHITE  kaptcha.image.width   验证码图片宽度  默认为200  kaptcha.image.height  验证码图片高度  默认为50