captcha验证码入门

Xml代码  

1. <servlet>  
2.         <servlet-name>Kaptcha</servlet-name>  
3.         <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>  
4.     </servlet>  
5.   
6.     <servlet-mapping>  
7.         <servlet-name>Kaptcha</servlet-name>  
8.         <url-pattern>/kaptcha</url-pattern>  
9.     </servlet-mapping>  

<servlet>
		<servlet-name>Kaptcha</servlet-name>
		<servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
	</servlet>

	<servlet-mapping>
		<servlet-name>Kaptcha</servlet-name>
		<url-pattern>/kaptcha</url-pattern>
	</servlet-mapping>

Html代码  

1. <div id="login" class="container" style="">  
2.         <h2>用户登录</h2>  
3.         <form action="#" method="post" accept-charset="utf-8"  
4.             class="navbar-form pull-left">  
5.             <img src="kaptcha" /> <br>  
6.             <input type="text" name="kaptcha" value="" /> <br>  
7.             <p><a class="btn btn-primary" id="upload_btn">上传 </a>  
8.         </form>  
9.     </div>  

<div id="login" class="container" style="">
		<h2>用户登录</h2>
		<form action="#" method="post" accept-charset="utf-8"
			class="navbar-form pull-left">
			<img src="kaptcha" /> <br>
			<input type="text" name="kaptcha" value="" /> <br>
			<p><a class="btn btn-primary" id="upload_btn">上传 </a>
		</form>
	</div>

Java代码  

1. String kaptchaExpected = (String)request.getSession() .getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);   
2. String kaptchaReceived = request.getParamater("kaptcha");   
3. if (kaptchaReceived == null || !kaptchaReceived.equalsIgnoreCase(kaptchaExpected)){ setError("kaptcha", "Invalid validation code.");}   

String kaptchaExpected = (String)request.getSession() .getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY); 
String kaptchaReceived = request.getParamater("kaptcha"); 
if (kaptchaReceived == null || !kaptchaReceived.equalsIgnoreCase(kaptchaExpected)){ setError("kaptcha", "Invalid validation code.");} 

Xml代码  

1. <servlet-name>Kaptcha</servlet-name>  
2.   <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>  
3.   <!-- 设置是否有边框 -->  
4.   <init-param>  
5.    <param-name>kaptcha.border</param-name>  
6.    <param-value>yes</param-value>  
7.   </init-param>  
8.   <!-- 设置边框颜色-->  
9.   <init-param>  
10.    <param-name>kaptcha.border.color</param-name>  
11.    <param-value>105,179,90</param-value>  
12.   </init-param>  
13.   <!-- 获取中文 -->  
14.   <init-param>  
15.    <param-name>kaptcha.textproducer.impl</param-name>  
16.    <param-value>org.cric.util.ChineseText</param-value>  
17.   </init-param>  
18.   <!-- 设置字体颜色 -->  
19.   <init-param>  
20.    <param-name>kaptcha.textproducer.font.color</param-name>  
21.    <param-value>black</param-value>  
22.   </init-param>  
23.   <!-- 设置验证码宽度 -->  
24.   <init-param>  
25.    <param-name>kaptcha.image.width</param-name>  
26.    <param-value>130</param-value>  
27.   </init-param>  
28.   <!-- 设置验证码高度 -->  
29.   <init-param>  
30.    <param-name>kaptcha.image.height</param-name>  
31.    <param-value>44</param-value>  
32.   </init-param>  
33.   <!-- 设置字体大小 -->  
34.   <init-param>  
35.    <param-name>kaptcha.textproducer.font.size</param-name>  
36.    <param-value>30</param-value>  
37.   </init-param>  
38.   <!-- 设置字体个数 -->  
39.   <init-param>  
40.    <param-name>kaptcha.textproducer.char.length</param-name>  
41.    <param-value>4</param-value>  
42.   </init-param>  
43.   <!-- 设置字体样式 -->  
44.   <init-param>  
45.    <param-name>kaptcha.textproducer.font.names</param-name>  
46.    <param-value>宋体,楷体,微软雅黑</param-value>  
47.   </init-param>  
48.   
49.  </servlet>  

<servlet-name>Kaptcha</servlet-name>
  <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
  <!-- 设置是否有边框 -->
  <init-param>
   <param-name>kaptcha.border</param-name>
   <param-value>yes</param-value>
  </init-param>
  <!-- 设置边框颜色-->
  <init-param>
   <param-name>kaptcha.border.color</param-name>
   <param-value>105,179,90</param-value>
  </init-param>
  <!-- 获取中文 -->
  <init-param>
   <param-name>kaptcha.textproducer.impl</param-name>
   <param-value>org.cric.util.ChineseText</param-value>
  </init-param>
  <!-- 设置字体颜色 -->
  <init-param>
   <param-name>kaptcha.textproducer.font.color</param-name>
   <param-value>black</param-value>
  </init-param>
  <!-- 设置验证码宽度 -->
  <init-param>
   <param-name>kaptcha.image.width</param-name>
   <param-value>130</param-value>
  </init-param>
  <!-- 设置验证码高度 -->
  <init-param>
   <param-name>kaptcha.image.height</param-name>
   <param-value>44</param-value>
  </init-param>
  <!-- 设置字体大小 -->
  <init-param>
   <param-name>kaptcha.textproducer.font.size</param-name>
   <param-value>30</param-value>
  </init-param>
  <!-- 设置字体个数 -->
  <init-param>
   <param-name>kaptcha.textproducer.char.length</param-name>
   <param-value>4</param-value>
  </init-param>
  <!-- 设置字体样式 -->
  <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>

captcha验证码入门

原文：http://blog.csdn.net/j2spark/article/details/51002925