Jcaptcha和Kaptcha验证码使用入门

本文主要是介绍Jcaptcha和Kaptcha验证码使用入门，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

原文地址：http://www.v5cn.cn/?p=157

一、jcaptcha验证码使用

jcaptcha使用默认样式生成的验证码比较难以识别，所以需要自定义验证码的样式，包括，背景色、背景大小、字体、字体大小、生成的字符数等。相对与kaptcha比较复杂。

1.1、纯代码实现jcaptcha验证码

1、首先创建一个javaWeb工程添加jcaptcha包和它所依赖的包，添加完成后：

2、创建一个jcaptcha单例的Service类，这里是设置验证码样式的关键部分，代码如下：

package cn.v5cn.jcaptchatest.custom;import java.awt.Font;import com.octo.captcha.CaptchaFactory;
import com.octo.captcha.component.image.backgroundgenerator.UniColorBackgroundGenerator;
import com.octo.captcha.component.image.color.RandomRangeColorGenerator;
import com.octo.captcha.component.image.fontgenerator.RandomFontGenerator;
import com.octo.captcha.component.image.textpaster.RandomTextPaster;
import com.octo.captcha.component.image.wordtoimage.ComposedWordToImage;
import com.octo.captcha.component.word.FileDictionary;
import com.octo.captcha.component.word.wordgenerator.ComposeDictionaryWordGenerator;
import com.octo.captcha.engine.GenericCaptchaEngine;
import com.octo.captcha.image.gimpy.GimpyFactory;
import com.octo.captcha.service.image.ImageCaptchaService;
import com.octo.captcha.service.multitype.GenericManageableCaptchaService;public class CaptchaServiceSingleton {private static ImageCaptchaService service = null;public static ImageCaptchaService getService(){if(service == null)service = generatorCaptchaService();return service;}/*** 根据SpringBean的配置文件编写的代码实现* */public static ImageCaptchaService generatorCaptchaService(){//生成随机颜色，参数分别表示RGBA的取值范围RandomRangeColorGenerator textColor = new RandomRangeColorGenerator(new int[]{0,255},new int[]{0,180},new int[]{0,210},new int[]{255,255});//随机文字多少和颜色，参数1和2表示最少生成多少个文字和最多生成多少个RandomTextPaster randomTextPaster = new RandomTextPaster(4, 5, textColor,true);//生成背景的大小这里是宽85高40的图片，也可以设置背景颜色和随机背景颜色，这里使用默认的白色UniColorBackgroundGenerator colorbgGen = new UniColorBackgroundGenerator(85,40);//随机生成的字体大小和字体类型，参数1和2表示最小和最大的字体大小，第三个表示随机的字体RandomFontGenerator randomFontGenerator = new RandomFontGenerator(20, 25, new Font[]{new Font("Arial", 0, 10),new Font("Tahoma",0,10)});//结合上面的对象构件一个从文本生成图片的对象ComposedWordToImage cwti = new ComposedWordToImage(randomFontGenerator,colorbgGen,randomTextPaster);//随机文本的字典，这里是使用jcaptcha-1.0-all.jar中的文本字典，字典名称为toddlist.propertiesComposeDictionaryWordGenerator cdwg = new ComposeDictionaryWordGenerator(new FileDictionary("toddlist"));GimpyFactory gf = new GimpyFactory(cdwg, cwti);GenericCaptchaEngine gce = new GenericCaptchaEngine(new CaptchaFactory[]{gf});//返回一个Service对象，这里180是验证码存在的时间，单位是秒，200000是最大存储大小return new GenericManageableCaptchaService(gce,180,200000,75000);}
}

每一句代码都有注释，这里就不多说了。

3、创建一个生成验证码的Servlet，代码如下：

package cn.v5cn.jcaptchatest.custom;import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;public class CustomServlet extends HttpServlet {private static final long serialVersionUID = 169310818225761427L;@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {byte[] captChallengeAsJpeg = null;ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();String captchaId = req.getSession().getId();BufferedImage challenge = CaptchaServiceSingleton.getService().getImageChallengeForID(captchaId,req.getLocale());JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(jpegOutputStream);jpegEncoder.encode(challenge);captChallengeAsJpeg = jpegOutputStream.toByteArray();resp.setHeader("Cache-Control", "no-store");resp.setHeader("Pragma", "no-cache");resp.setDateHeader("Expires", 0);resp.setContentType("image/jpeg");ServletOutputStream respOutputStream = resp.getOutputStream();respOutputStream.write(captChallengeAsJpeg);respOutputStream.flush();respOutputStream.close();}
}

4、在Web.xml中注册这个Servlet，代码如下：

<servlet><servlet-name>generateValidateCode</servlet-name><servlet-class>cn.v5cn.jcaptchatest.custom.CustomServlet</servlet-class></servlet><servlet-mapping><servlet-name>generateValidateCode</servlet-name><url-pattern>/cgvc</url-pattern></servlet-mapping>

5、编写一个使用验证码的页面，代码如下：

<form action="valiServlet" method="post"><input type="text" name="customgvc"><img id="vcode" title="点击更换" alt="验证图片" style="vertical-align: middle;" src="cgvc" height="30" width="80"><input type="submit" value="提交">
</form>

6、编写一个验证Servlet并在web.xml中注册，代码分别如下：

package cn.v5cn.jcaptchatest.custom;import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class ValidateServlet extends HttpServlet {private static final long serialVersionUID = -7173743572400866269L;@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {String captchaId = req.getSession().getId();String validateCode = req.getParameter("customgvc");boolean validateResult = CaptchaServiceSingleton.getService().validateResponseForID(captchaId, validateCode);if(validateResult)resp.sendRedirect("success.html");elseresp.sendRedirect("fail.html");}
}

<servlet><servlet-name>validatServlet</servlet-name><servlet-class>cn.v5cn.jcaptchatest.custom.ValidateServlet</servlet-class></servlet><servlet-mapping><servlet-name>validatServlet</servlet-name><url-pattern>/valiServlet</url-pattern></servlet-mapping>

7、运行会看到验证码如下：

8、输入验证码点击提交，看是否可以验证通过，如果一切正常的话Session中的和提交的是一致的。

1.2、使用Spring配置jcaptha验证码

1、创建一个javaWeb工程并加入Spring和jcaptcha的包。添加完成后的包依赖如下：

2、在web.xml中配置Spring代码如下：

<context-param><param-name>contextConfigLocation</param-name><param-value>/WEB-INF/spring-jcaptcha.xml</param-value></context-param><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener>

3、在WEB-INF中创建spring-jcaptcha.xml的SpringBean配置文件，代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd"><!-- 构建生成图片服务 --><bean id="imageCaptchaService"  class="com.octo.captcha.service.multitype.GenericManageableCaptchaService"><constructor-arg index="0" ref="imageEngine"/><constructor-arg index="1" value="180"/><constructor-arg index="2" value="200000"/><constructor-arg index="3" value="75000"/></bean><!-- 构建生成图片引擎，可以传入多个ImageCaptchaFactory工厂 --><bean id="imageEngine" class="com.octo.captcha.engine.GenericCaptchaEngine"><constructor-arg index="0"><list><ref bean="imageCaptchaFactory"/></list></constructor-arg></bean><!-- 构件图片工厂 ，图片工厂包括FishEyeFactory和GimpyFactory 它们都继承自ImageCaptchaFactory抽象类--><bean id="imageCaptchaFactory" class="com.octo.captcha.image.gimpy.GimpyFactory" ><constructor-arg><ref bean="wordgen"/></constructor-arg><constructor-arg><ref bean="wordtoimage"/></constructor-arg></bean><!-- 构件验证码上的文本生成类 --><bean id="wordgen" class="com.octo.captcha.component.word.wordgenerator.ComposeDictionaryWordGenerator" ><constructor-arg index="0" ref="filedict"/></bean><!-- 构件文件字典类，读取文件字典 。该文件字典包含在jcaptcha-1.0-all.jar 包的toddlist.properties 文件--><bean id="filedict" class="com.octo.captcha.component.word.FileDictionary" ><constructor-arg index="0" value="toddlist"/></bean><!-- 构件一个从文本到图片的生成类 --><bean id="wordtoimage" class="com.octo.captcha.component.image.wordtoimage.ComposedWordToImage" ><constructor-arg index="0"><ref bean="fontGenRandom"/></constructor-arg><constructor-arg index="1"><ref bean="backGenUni"/></constructor-arg><constructor-arg index="2"><ref bean="simpleColoredPaster"/></constructor-arg></bean><!-- 构件一个生成随机字体的类 。第一个参数是最小字体大小，第二个参数是最大字体大小，第三个参数是随机的字体列表这里定义了5种类型的字体--><bean id="fontGenRandom" class="com.octo.captcha.component.image.fontgenerator.RandomFontGenerator" ><constructor-arg index="0"><value>20</value></constructor-arg><constructor-arg index="1"><value>25</value></constructor-arg><constructor-arg index="2"><list><bean class="java.awt.Font"><constructor-arg index="0" value="Arial"/><constructor-arg index="1" value="0"/><constructor-arg index="2" value="10"/></bean><bean class="java.awt.Font" ><constructor-arg index="0" value="Tahoma"/><constructor-arg index="1" value="1"/><constructor-arg index="2" value="10"/></bean><bean class="java.awt.Font" ><constructor-arg index="0" value="Verdana"/><constructor-arg index="1" value="0"/><constructor-arg index="2" value="10"/></bean><bean class="java.awt.Font" ><constructor-arg index="0" value="Comic sans MS"/><constructor-arg index="1" value="0"/><constructor-arg index="2" value="10"/></bean><bean class="java.awt.Font" ><constructor-arg index="0" value="Lucida console"/><constructor-arg index="1" value="0"/><constructor-arg index="2" value="10"/></bean></list></constructor-arg></bean><!-- 构件一个背景大小生成类 ，第一个参数是背景宽度，第二个参数是背景高度--><bean id="backGenUni" class="com.octo.captcha.component.image.backgroundgenerator.UniColorBackgroundGenerator" ><constructor-arg index="0"><value>85</value></constructor-arg><constructor-arg index="1"><value>40</value></constructor-arg></bean><!-- 构件一个随机文本个数和颜色，第一个参数是最少文本个数，第二个参数是最多文本个数 --><bean id="simpleColoredPaster" class="com.octo.captcha.component.image.textpaster.RandomTextPaster" ><constructor-arg index="0" value="4"/><constructor-arg index="1" value="5"/><constructor-arg type="com.octo.captcha.component.image.color.ColorGenerator" index="2" ref="colorGenRandomDark"/><constructor-arg index="3" value="true"/></bean><!-- 构件一个随机的颜色，参数分别代表RGBA通道的取值范围 --><bean id="colorGenRandomDark" class="com.octo.captcha.component.image.color.RandomRangeColorGenerator" ><constructor-arg index="0"><list><value>0</value><value>255</value></list></constructor-arg><constructor-arg index="1"><list><value>0</value><value>185</value></list></constructor-arg><constructor-arg index="2"><list><value>0</value><value>200</value></list></constructor-arg><constructor-arg index="3"><list><value>255</value><value>255</value></list></constructor-arg></bean></beans>

各种配置与代码实现是一样的，每个配置中都有注释。

4、编写一个生成验证码的Servlet，代码如下：

package cn.v5cn.jcaptchatest.spring;import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;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 org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;import com.octo.captcha.service.CaptchaServiceException;
import com.octo.captcha.service.image.ImageCaptchaService;public class JcaptchaServlet extends HttpServlet {private static final long serialVersionUID = -8021621053846019170L;public static final String CAPTCHA_IMAGE_FORMAT = "jpeg";private ImageCaptchaService captchaService;@Overridepublic void init() throws ServletException {WebApplicationContext appCtx = WebApplicationContextUtils.getWebApplicationContext(getServletContext());captchaService = (ImageCaptchaService) BeanFactoryUtils.beanOfTypeIncludingAncestors(appCtx, ImageCaptchaService.class);}@Overrideprotected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {byte[] captchaChallengeAsJpeg = null;ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();try {String captchaId = request.getSession().getId();BufferedImage challenge = captchaService.getImageChallengeForID(captchaId, request.getLocale());ImageIO.write(challenge, CAPTCHA_IMAGE_FORMAT, jpegOutputStream);} catch (IllegalArgumentException e) {response.sendError(HttpServletResponse.SC_NOT_FOUND);return;} catch (CaptchaServiceException e) {response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);return;}captchaChallengeAsJpeg = jpegOutputStream.toByteArray();// flush it in the responseresponse.setHeader("Cache-Control", "no-store");response.setHeader("Pragma", "no-cache");response.setDateHeader("Expires", 0);response.setContentType("image/" + CAPTCHA_IMAGE_FORMAT);ServletOutputStream responseOutputStream = response.getOutputStream();responseOutputStream.write(captchaChallengeAsJpeg);responseOutputStream.flush();responseOutputStream.close();}
}

5、在web.xml中注册这Servlet，代码如下：

<servlet><servlet-name>springCaptcha</servlet-name><servlet-class>cn.v5cn.jcaptchatest.spring.JcaptchaServlet</servlet-class></servlet><servlet-mapping><servlet-name>springCaptcha</servlet-name><url-pattern>/scgvc</url-pattern></servlet-mapping>

6、验证步骤与代码实现一样，请大家自行编写。

二、kaptcha验证码使用

个人感觉kaptcha使用比jcaptcha相对简单。

1、在Servelt中配置kaptcha的Servlet，代码如下：

<!-- 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.textproducer.font.color</param-name><param-value>black</param-value></init-param><init-param><param-name>kaptcha.textproducer.char.space</param-name><param-value>5</param-value></init-param></servlet><servlet-mapping><servlet-name>kaptcha</servlet-name><url-pattern>/kaptcha.jpg</url-pattern></servlet-mapping>

kaptcha.border：是否显示边框。

kaptcha.textproducer.font.color：字体颜色

kaptcha.textproducer.char.space：字符间距

更多的属性设置可以在com.google.code.kaptcha.Constants类中找到。其中包括：

kaptcha.border.color：边框颜色

kaptcha.border.thickness：边框宽度

kaptcha.textproducer.char.length：产生字符的长度

kaptcha.textproducer.font.size：产生字符的大小

kaptcha.image.width：产生图片的宽度

kaptcha.image.height：产生图片的高度，等

2、编写一个显示验证码的页面，代码如下：

<form action="kaptcha" method="post"><input type="text" name="kaptchaValidate"><img id="vcode" style="vertical-align: middle;" title="点击更换" alt="验证图片" src="kaptcha.jpg" height="40" width="85"><input type="submit" value="提交"></form>

3、运行页面显示如下：

4、编写一个验证的Servelt，代码如下：

package cn.v5cn.kaptcha;import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.google.code.kaptcha.Constants;public class KaptchaValidateServlet extends HttpServlet {private static final long serialVersionUID = -7642000788132875193L;@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {String validate = req.getParameter("kaptchaValidate");String validateCode = (String) req.getSession().getAttribute(Constants.KAPTCHA_SESSION_KEY);if(validate==null || validateCode == null){resp.sendRedirect("fail.html");}else if(!validateCode.equals(validate)){resp.sendRedirect("fail.html");}else{resp.sendRedirect("success.html");}}
}