kaptcha验证码使用

淩亂°似流年 2022-08-10 10:55 240阅读 0赞

效果图

![这里写图片描述][20151121101454431]

1、把下载的kaptcha-2.3.2.jar添加到lib中

2、配置web.xml增加servlet

Kaptcha  
com.google.code.kaptcha.servlet.KaptchaServlet  
  
  
Kaptcha  
/kaptcha.jpg  
  
3、在jsp页面中

其中src=”kaptcha.jpg”会被定位到servlet上

4、KaptchaServlet会把验证码设置到session中，可以如下方式获取

String kaptchaExpected = (String)request.getSession()  
.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA\_SESSION\_KEY);  
5、如果是struts2的action，可以如下方式获取

String kaptchaExpected = (String)ActionContext.getContext().getSession()  
.get(com.google.code.kaptcha.Constants.KAPTCHA\_SESSION\_KEY);  
6、如果想设置点击图片更换验证码，可以加上如下js，需要jquery

(function()\{  ('\#kaptchaImage').click(function () \{ $(this).attr('src', '/kaptcha.jpg?' + Math.floor(Math.random()\*100) ); \}) \});

7、或者来点fade效果

(function() \{  ('\#kaptchaImage').click( function() \{ $(this).hide().attr('src', 'kaptcha.jpg?' + Math.floor(Math.random() \* 100)).fadeIn(); \}); \});

8、验证码图片还有很多参数设置

设置方法，在web.xml的servlet中

<init-param>
            <param-name>kaptcha.border</param-name>
            <param-value>no</param-value>
        </init-param>

![这里写图片描述][20151121101836342]  
![这里写图片描述][20151121101914253]

<!--
        <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>

具体效果：

![这里写图片描述][20151121101943319]

[20151121101454431]: /images/20220731/f3875b1c117c439abd8e56452b43d2b8.png
[20151121101836342]: /images/20220731/77309f558c9d4f79ba976ea3fe68d69c.png
[20151121101914253]: /images/20220731/a881ab4d2b9c46a8855ab9ecb525e6e4.png
[20151121101943319]: /images/20220731/d44ebfaa8d354994b7b1a488d1353f9e.png