jcaptcha和kaptcha验证码使用入门 - CMU开源的web图片验证码项目

转自：https://www.cnblogs.com/whatlonelytear/p/6270259.html

jcaptcha和kaptcha验证码使用入门

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.properties
        ComposeDictionaryWordGenerator 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;
     
    @Override
    protected 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;
     
    @Override
    protected 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");
        else
            resp.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;
 
    @Override
    public void init() throws ServletException {
        WebApplicationContext appCtx = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
         
        captchaService = (ImageCaptchaService) BeanFactoryUtils.beanOfTypeIncludingAncestors(appCtx, ImageCaptchaService.class);
    }
 
    @Override
    protected 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 response
        response.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;
     
    @Override
    protected 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");
        }
    }
}

三、总结：

到处jcaptcha和kaptcha的验证代码就编写完成了，写的还比较浅显。希望对需要这两个验证码包的朋友有所帮助，也是给自己一个备忘。

全引用自: 此条目由zyw090111发表在Spring分类目录，并贴了jcaptcha、kaptcha、验证码标签。将固定链接加入收藏夹。

四、其它较新资源:

浅析Java验证码生成库JCaptcha

五、遇到异常

jcaptcha组件小小改造解决Invalid ID, could not validate unexisting or already validated captcha

作者：whatlonelytear
本文地址：https://www.cnblogs.com/whatlonelytear/p/6270259.html
欢迎转载，请在明显位置给出出处及链接。