kaptcha 验证码在spring mvc 中的使用

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/

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  -->
<!--
    <
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
>

Xml代码

    
<
servlet-mapping
>
<
servlet-name
>
kaptcha
</
servlet-name
>
<
url-pattern
>
/ClinicCountManager/kaptcha.jpg
</
url-pattern
>
lt;/servlet-mapping>

 

jsp 页面使用

<table>
        <tr>
            <td><img src="/ClinicCountManager/kaptcha.jpg"
></td>
            <td valign="top"
>

                <form method="POST"
>
                    <br>sec code:<input type="text"
 name=
"kaptchafield"
><br />
                    <input type="submit"
 name=
"submit"
>
                </form>
            </td>
        </tr>
    </table>

    <br /><br /><br /><br />

    <%
        String c = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
        String parm = (String) request.getParameter("kaptchafield"
);

        out.println("Parameter: "
 + parm + 
" ? Session Key: "
 + c + 
" : "
);

        if
 (c != 
null
 && parm != 
null
) {
            if
 (c.equals(parm)) {
                out.println("<b>true</b>"
);
            } else
 {
                out.println("<b>false</b>"
);
            }

    %>

 

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applicationContext.xml中配置

 

Xml代码 

<
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
>

 

新建生成图片控制类

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

 

Java代码

<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

 

Java代码

String code = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);