使用kaptcha可以方便的配置：
- 验证码的字体
- 验证码字体的大小
- 验证码字体的字体颜色
- 验证码内容的范围(数字，字母，中文汉字！)
- 验证码图片的大小，边框，边框粗细，边框颜色
- 验证码的干扰线(可以自己继承com.google.code.kaptcha.NoiseProducer写一个自定义的干扰线)
- 验证码的样式(鱼眼样式、3D、普通模糊……当然也可以继承com.google.code.kaptcha.GimpyEngine自定义样式)
……
详细信息请看下面的web.xml文件
下面介绍一下用法:
1.首先去官网下载jar:http://code.google.com/p/kaptcha/
2.建立一个web项目，导入kaptcha-2.3.jar到环境变量中。
3.配置web.xml文件
<!-- Kaptcha验证码配置 --> <servlet> <servlet-name>Kaptcha</servlet-name> <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class> <init-param> <param-name>kaptcha.border</param-name> <param-value>no</param-value> </init-param> <init-param> <param-name>kaptcha.border.color</param-name> <param-value>105,179,90</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.color</param-name> <param-value>red</param-value> </init-param> <init-param> <param-name>kaptcha.obscurificator.impl</param-name> <param-value>com.google.code.kaptcha.impl.FishEyeGimpy</param-value> </init-param> <init-param> <param-name>kaptcha.image.width</param-name> <param-value>250</param-value> </init-param> <init-param> <param-name>kaptcha.image.height</param-name> <param-value>90</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.size</param-name> <param-value>70</param-value> </init-param> <init-param> <!-- String kaptchaExpected = (String) session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY); 必须改成 String kaptchaExpected = (String) session.getAttribute("code"); --> <param-name>kaptcha.session.key</param-name> <param-value>code</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.char.length</param-name> <param-value>4</param-value> </init-param> <init-param> <param-name>kaptcha.textproducer.font.names</param-name> <param-value>宋体,楷体,微软雅黑</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>Kaptcha</servlet-name> <url-pattern>/kaptcha</url-pattern> </servlet-mapping>
4. jsp 页面使用
<form class="m-t" role="form" id="loginform" method="post" action=""> <div class="form-group"><input class="form-control" name="userAccount" placeholder="用户名" required=""></div> <div class="form-group"><input type="password" class="form-control" name="userPwd" placeholder="密码" required=""></div> <input type="text" class="form-control login-yan-w" id="kaptcha" name="kaptcha" placeholder="验证码"> <span class="login-w"><img id="kaptchaImage" src="kaptcha"></span> <input type="button" class="btn btn-primary block full-width m-b" onclick="login()" value="登 录"> </form>
function login(){ $.ajax({ cache: true, type: "POST", url:'${pageContext.request.contextPath}/login', data:$('#loginform').serialize(), dataType:'json', success: function(data) { if(data.status==200){ url="<%=request.getContextPath()%>/index.jsp"; window.location.href=url; }else{ alert(data.msg) } }, error: function(){ alert("请检查用户账户或密码"); } }); }
5. 如果想设置点击图片更换验证码，可以加上如下js
<script type="text/javascript">
//点击图片验证码进行更新
$(function(){
$('#kaptchaImage').click(function () { $(this).attr('src', 'kaptcha?' + Math.floor(Math.random()*100) ); })
});
</script>
5. KaptchaServlet会把验证码设置到session中，在Controller可以如下方式获取
@RequestMapping("/login")
@ResponseBody
public CRMResult login(HttpServletRequest request ,HttpSession session) {
String kaptcha = request.getParameter("kaptcha");
String kaptchaExpected = (String) session.getAttribute("code");
System.out.println(kaptcha +"......"+kaptchaExpected);
if (!kaptcha.equalsIgnoreCase(kaptchaExpected)) {
return CRMResult.build(201, "验证码填写错误");
}
return CRMResult.ok();
}
上面的配置在普通jsp环境下面是有效的，如果在spring mvc环境下，则取不到session值，对于sping mvc环境验证码配置如下：
１.不用在web.xml进行相关配置，在springmvc.xml中配置
<bean id="captchaProducer" class="com.google.code.kaptcha.impl.DefaultKaptcha"> <property name="config"> <bean class="com.google.code.kaptcha.util.Config"> <constructor-arg> <props> <prop key="kaptcha.border">no</prop> <prop key="kaptcha.border.color">105,179,90</prop> <prop key="kaptcha.textproducer.font.color">red</prop> <prop key="kaptcha.image.width">250</prop> <prop key="kaptcha.textproducer.font.size">90</prop> <prop key="kaptcha.image.height">90</prop> <prop key="kaptcha.session.key">code</prop> <prop key="kaptcha.textproducer.char.length">4</prop> <prop key="kaptcha.textproducer.font.names">宋体,楷体,微软雅黑</prop> </props> </constructor-arg> </bean> </property> </bean>
Java代码
import java.awt.image.BufferedImage; 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; @Controller @RequestMapping("/") public class CaptchaImageCreateController { private Producer captchaProducer = null; @Autowired public void setCaptchaProducer(Producer captchaProducer) { this.captchaProducer = captchaProducer; } @RequestMapping("/captcha-image") public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { 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); // 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; } }
前台调用方式
<div class="chknumber"> <label>验证码： <input name="kaptcha" type="text" id="kaptcha" maxlength="4" class="chknumber_input" /> </label> <img src="/ClinicCountManager/captcha-image.do" width="55" height="20" id="kaptchaImage" style="margin-bottom: -3px"/> <script type="text/javascript"> $(function(){ $('#kaptchaImage').click(function () {//生成验证码 $(this).hide().attr('src', '/ClinicCountManager/captcha-image.do?' + Math.floor(Math.random()*100) ).fadeIn(); }) }); </script> </div>
取验证码的方式
String code = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
如果需要全部数字
<init-param> <param-name>kaptcha.textproducer.char.string</param-name> <param-value>0123456789</param-value> </init-param>
去掉干扰线
<init-param> <param-name>kaptcha.noise.impl</param-name> <param-value>com.google.code.kaptcha.impl.NoNoise </param-value> </init-param>
