Java验证码生成库kaptcha使用简介

2016-06-12· 2491 次浏览
## kaptcha kaptcha 是一个非常实用的验证码生成工具。有了它,你可以生成各种样式的验证码,因为它是可配置的。kaptcha工作的原理是调用 com.google.code.kaptcha.servlet.KaptchaServlet,生成一个图片。同时将生成的验证码字符串放到 HttpSession中。 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/](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。 ## Servlet方式 配置web.xml文件,之后访问 /kaptcha.jpg ``` <!--Kaptcha 验证码 --> <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.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> <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.jpg</url-pattern> </servlet-mapping> ``` ## 配置验证码生成器 在applicationContext.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> ``` ## SpringMVC图片生成器 ``` 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.jpg") 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; } } ``` ## Struts2图片生成器 访问的URL请自行配置,这里的image方法可以向浏览器输出图片流; ``` package com.zhenzhigu.ssh.action; import java.awt.image.BufferedImage; import java.io.OutputStream; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts2.ServletActionContext; import org.springframework.beans.factory.annotation.Autowired; import com.google.code.kaptcha.Constants; import com.google.code.kaptcha.Producer; import com.opensymphony.xwork2.ActionSupport; public class ValidateCodeImage extends ActionSupport { @Autowired private Producer captchaProducer = null; public String image() throws Exception { HttpServletRequest request = ServletActionContext.getRequest(); HttpServletResponse response = ServletActionContext.getResponse(); response.setDateHeader("Expires", 0); //禁用浏览器缓存 response.setHeader("Cache-Control","no-store, no-cache, must-revalidate"); response.addHeader("Cache-Control", "post-check=0, pre-check=0"); response.setHeader("Pragma", "no-cache"); //设置MIME类型为jpg response.setContentType("image/jpeg"); //创建一个验证码字符串 String capText = captchaProducer.createText(); //把字符串存到HttpSession中 request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY,capText); //生成验证码图片 BufferedImage bi = captchaProducer.createImage(capText); OutputStream out = response.getOutputStream(); //通过输出流把图片写到用户的浏览器中 ImageIO.write(bi, "jpg", out); return null; } } ``` ## 页面获取验证码图片 图片路径请根据实际情况填写。 ``` <img src="/captcha.jpg" width="55" height="20" id="vci"/> <script type="text/javascript"> $(function(){ //点击刷新 $('#vci').click(function(){ $(this).attr('src', '/captcha.jpg' + Math.random() ); }) }); </script> <br> $(function(){ //点击刷新<br> $('#vci').click(function(){ $(this).attr('src', '/captcha.jpg' + Math.random() ); })<br> }); ``` ## Java取验证码 ``` String code = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY); ``` ## 验证码相关设置 ### 全部都是数字 ``` <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> ```