jcaptcha验证码学习

原文->http://wwwzhouhui.iteye.com/blog/410935

现在项目中用SPRING 比较多所以整合了一下。其中的部分代码是参考一个jeecms项目的，讲其中的jcaptcha验证码这块剥离出来。 
  项目在上篇基础上编写的，部分代码是上篇中的代码(偷懒了) 
1.用到得JAR 
   commons-logging.jar,jcaptcha-all-1.0-RC6.jar,spring-beans-2.5.6.jar 
   spring-context-2.5.6.jar,spring-core-2.5.6.jar,spring-web-2.5.6.jar 
2.applicationContext.xml 

 <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
    >
    <!--验证码生成器-->
    <bean id="imageCaptchaService" class="com.spring.CaptchaService">
        <constructor-arg type="com.octo.captcha.service.captchastore.CaptchaStore" index="0">
            <ref bean="fastHashMapCaptchaStore"/>
        </constructor-arg>
        <!--which captcha Engine you use-->
        <constructor-arg type="com.octo.captcha.engine.CaptchaEngine" index="1">
            <ref bean="captchaEngineEx"/>
        </constructor-arg>
        <constructor-arg index="2">
            <value>180</value>
        </constructor-arg>
        <constructor-arg index="3">
            <value>100000</value>
        </constructor-arg>
        <constructor-arg index="4">
            <value>75000</value>
        </constructor-arg>
    </bean>
    <bean id="fastHashMapCaptchaStore" class="com.octo.captcha.service.captchastore.FastHashMapCaptchaStore"/>
    <!--you can define more than one captcha engine here -->
    <bean id="captchaEngineEx" class="com.spring.CaptchaEngineEx"/>
</beans>

3. web.xml 

 <?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            classpath:applicationContext.xml
        </param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <!--
    <servlet>
        <servlet-name>jcaptcha</servlet-name>
        <servlet-class>com.code.ImageCaptchaServlet</servlet-class>
        <load-on-startup>0</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>jcaptcha</servlet-name>
        <url-pattern>/jcaptcha</url-pattern>
    </servlet-mapping>
    -->

    <servlet>
        <servlet-name>jcaptcha2</servlet-name>
        <servlet-class>com.spring.ImageCaptchaServlet</servlet-class>
        <load-on-startup>0</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>jcaptcha2</servlet-name>
        <url-pattern>/jcaptcha</url-pattern>
    </servlet-mapping>
    <!--
    <servlet>
        <servlet-name>checkjcaptcha</servlet-name>
        <servlet-class>com.code.ValidationServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>checkjcaptcha</servlet-name>
        <url-pattern>/validateAction</url-pattern>
    </servlet-mapping>
    -->
    <servlet>
        <servlet-name>checkjcaptcha2</servlet-name>
        <servlet-class>com.spring.ValidationServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>checkjcaptcha2</servlet-name>
        <url-pattern>/validateAction</url-pattern>
    </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

4.java 代码 
   自定义生成代码部分 
   CaptchaEngineEx.java 
 

package com.spring;

import java.awt.Color;

import com.octo.captcha.component.image.backgroundgenerator.BackgroundGenerator;
import com.octo.captcha.component.image.backgroundgenerator.GradientBackgroundGenerator;
import com.octo.captcha.component.image.color.SingleColorGenerator;
import com.octo.captcha.component.image.fontgenerator.FontGenerator;
import com.octo.captcha.component.image.fontgenerator.RandomFontGenerator;
import com.octo.captcha.component.image.textpaster.DecoratedRandomTextPaster;
import com.octo.captcha.component.image.textpaster.TextPaster;
import com.octo.captcha.component.image.textpaster.textdecorator.BaffleTextDecorator;
import com.octo.captcha.component.image.textpaster.textdecorator.LineTextDecorator;
import com.octo.captcha.component.image.textpaster.textdecorator.TextDecorator;
import com.octo.captcha.component.image.wordtoimage.ComposedWordToImage;
import com.octo.captcha.component.image.wordtoimage.WordToImage;
import com.octo.captcha.component.word.wordgenerator.RandomWordGenerator;
import com.octo.captcha.component.word.wordgenerator.WordGenerator;
import com.octo.captcha.engine.image.ListImageCaptchaEngine;
import com.octo.captcha.image.gimpy.GimpyFactory;

/***********************************************************************
 *
 *   CaptchaEngineEx.java
 *   @copyright       Copyright:   2009-2012
 *   @creator         周辉<br/>
 *   @create-time   Jun 18, 2009   2:41:12 PM
 *   @revision         $Id:     *
 ***********************************************************************/
public class CaptchaEngineEx extends ListImageCaptchaEngine {

    protected void buildInitialFactories() {
        // Set Captcha Word Length Limitation which should not over 6
        Integer minAcceptedWordLength = new Integer(4);
        Integer maxAcceptedWordLength = new Integer(5);
        // Set up Captcha Image Size: Height and Width
        Integer imageHeight = new Integer(40);
        Integer imageWidth = new Integer(100);

        // Set Captcha Font Size
        Integer minFontSize = new Integer(20);
        Integer maxFontSize = new Integer(22);
        // We just generate digit for captcha source char Although you can use
        // abcdefghijklmnopqrstuvwxyz
        WordGenerator wordGenerator = new RandomWordGenerator("0123456789");

        // cyt and unruledboy proved that backgroup not a factor of Security. A
        // captcha attacker won't affaid colorful backgroud, so we just use
        // white
        // color, like google and hotmail.
        BackgroundGenerator backgroundGenerator = new GradientBackgroundGenerator(
                imageWidth, imageHeight, Color.white, Color.white);

        // font is not helpful for security but it really increase difficultness
        // for
        // attacker
        FontGenerator fontGenerator = new RandomFontGenerator(minFontSize,
                maxFontSize);
        // Note that our captcha color is Blue
        SingleColorGenerator scg = new SingleColorGenerator(Color.blue);

        // decorator is very useful pretend captcha attack. we use two line text
        // decorators.

        LineTextDecorator lineDecorator = new LineTextDecorator(1, Color.blue);
        // LineTextDecorator line_decorator2 = new LineTextDecorator(1,
        // Color.blue);
        TextDecorator[] textdecorators = new TextDecorator[1];

        textdecorators[0] = lineDecorator;
        // textdecorators[1] = line_decorator2;

        TextPaster textPaster = new DecoratedRandomTextPaster(
                minAcceptedWordLength, maxAcceptedWordLength, scg,
                new TextDecorator[] { new BaffleTextDecorator(new Integer(1),
                        Color.white) });

        // ok, generate the WordToImage Object for logon service to use.
        WordToImage wordToImage = new ComposedWordToImage(fontGenerator,
                backgroundGenerator, textPaster);
        addFactory(new GimpyFactory(wordGenerator, wordToImage));

    }

}

生成图片的servlet 
ImageCaptchaServlet.JAVA 

package com.spring;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.servlet.ServletConfig;
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.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.octo.captcha.service.CaptchaServiceException;
import com.octo.captcha.service.image.ImageCaptchaService;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/***********************************************************************
 *
 *   ImageCaptchaServlet.java
 *   @copyright       Copyright:   2009-2012
 *   @creator         周辉<br/>
 *   @create-time   Jun 18, 2009   2:44:15 PM
 *   @revision         $Id:     *
 ***********************************************************************/
@SuppressWarnings("serial")
public class ImageCaptchaServlet extends HttpServlet {
    private ImageCaptchaService imageCaptchaService;
    private String beanName = "imageCaptchaService";

    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);
        WebApplicationContext wac = WebApplicationContextUtils
                .getRequiredWebApplicationContext(servletConfig
                        .getServletContext());
        imageCaptchaService = (ImageCaptchaService) wac.getBean(beanName,
                ImageCaptchaService.class);
    }

    protected void doGet(HttpServletRequest httpServletRequest,
            HttpServletResponse httpServletResponse) throws ServletException,
            IOException {

        byte[] captchaChallengeAsJpeg = null;
        // the output stream to render the captcha image as jpeg into
        ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();
        try {
            // get the session id that will identify the generated captcha.
            // the same id must be used to validate the response, the session id
            // is a good candidate!
            String captchaId = httpServletRequest.getSession().getId();
            // call the ImageCaptchaService getChallenge method
            BufferedImage challenge = imageCaptchaService
                    .getImageChallengeForID(captchaId, httpServletRequest
                            .getLocale());

            // a jpeg encoder
            JPEGImageEncoder jpegEncoder = JPEGCodec
                    .createJPEGEncoder(jpegOutputStream);
            jpegEncoder.encode(challenge);
        } catch (IllegalArgumentException e) {
            httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        } catch (CaptchaServiceException e) {
            httpServletResponse
                    .sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            return;
        }

        captchaChallengeAsJpeg = jpegOutputStream.toByteArray();

        // flush it in the response
        httpServletResponse.setHeader("Cache-Control", "no-store");
        httpServletResponse.setHeader("Pragma", "no-cache");
        httpServletResponse.setDateHeader("Expires", 0);
        httpServletResponse.setContentType("image/jpeg");
        ServletOutputStream responseOutputStream = httpServletResponse
                .getOutputStream();
        responseOutputStream.write(captchaChallengeAsJpeg);
        responseOutputStream.flush();
        responseOutputStream.close();
    }
}

验证的单列类 CaptchaService.java 

package com.spring;

import com.octo.captcha.engine.CaptchaEngine;
import com.octo.captcha.service.captchastore.CaptchaStore;
import com.octo.captcha.service.image.DefaultManageableImageCaptchaService;

/***********************************************************************
 *
 *   CaptchaService.java
 *   @copyright       Copyright:   2009-2012
 *   @creator         周辉<br/>
 *   @create-time   Jun 18, 2009   2:42:53 PM
 *   @revision         $Id:     *
 ***********************************************************************/
public class CaptchaService extends DefaultManageableImageCaptchaService {
    public CaptchaService() {
        super();
    }

    public CaptchaService(int minSeconds, int maxStoreSize, int loadBefore) {
        super(minSeconds, maxStoreSize, loadBefore);
    }

    public CaptchaService(CaptchaStore captchaStore,
            CaptchaEngine captchaEngine, int minSeconds, int maxStoreSize,
            int loadBefore) {
        super(captchaStore, captchaEngine, minSeconds, maxStoreSize, loadBefore);
    }

    public Boolean validateResponseForID(String ID, Object response) {
        Boolean isHuman;
        try {
            isHuman = super.validateResponseForID(ID, response);
        } catch (Exception e) {
            isHuman = false;
        }
        return isHuman;
    }
}

最后测试验证的类 
ValidationServlet.java 

package com.spring;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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;

/***********************************************************************
 *
 *   ValidationServlet.java
 *   @copyright       Copyright:   2009-2012
 *   @creator         周辉<br/>
 *   @create-time   Jun 18, 2009   3:16:50 PM
 *   @revision         $Id:     *
 ***********************************************************************/
public class ValidationServlet extends HttpServlet {
    private ImageCaptchaService imageCaptchaService;
    private String beanName = "imageCaptchaService";
    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);
        WebApplicationContext wac = WebApplicationContextUtils
        .getRequiredWebApplicationContext(servletConfig
                .getServletContext());
        imageCaptchaService = (ImageCaptchaService) wac.getBean(beanName,
                ImageCaptchaService.class);
    }

    protected void doGet(HttpServletRequest httpServletRequest,
            HttpServletResponse httpServletResponse) throws ServletException,
            IOException {

        Boolean isResponseCorrect = Boolean.FALSE;
        //remenber that we need an id to validate!
        String captchaId = httpServletRequest.getSession().getId();
        //retrieve the response
        String response = httpServletRequest.getParameter("j_captcha_response");
        // Call the Service method
        try {
            isResponseCorrect=imageCaptchaService.validateResponseForID(captchaId, response);
        } catch (CaptchaServiceException e) {
            //should not happen, may be thrown if the id is not valid
        }
        System.out.println(isResponseCorrect);
       // httpServletResponse.encodeUrl("sucess.html");
        if(isResponseCorrect.booleanValue()){
            httpServletResponse.sendRedirect("success.html");
        }
        else {
             httpServletResponse.sendRedirect("failture.html");
        }
    }
}

5 页面HTML 
  login2.html 

<html>
  <head>
    <title>MyHtml.html</title>

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="this is my page">
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">

    <!--<link rel="stylesheet" type="text/css" href="./styles.css">-->

  </head>

  <body>
    <form name="f1" id="f1" action="/jcaptcha/validateAction" method="get">
      <table border="0">
        <tr>
          <td>验证码:</td>
          <td><img src="jcaptcha"><input type='text' name='j_captcha_response' value=''></td>
        </tr>
        <tr>
          <td colspan="2" align="center"><input type="submit"></td>
        </tr>
      </table>

    </form>
  </body>
</html>

6 最后调用成功失败的页面success.html failture.html(略) 
最后发布程序，启动TOMCAT 输入 
http://localhost:8081/jcaptcha/login2.html 
看到生成验证码了