kaptcha验证码配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
version="3.0">
  <display-name></display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
    <!-- ==========================kaptcha验证码配置========================== -->
    <servlet>
        <!-- 生成图片的Servlet -->
        <servlet-name>kaptchaCode</servlet-name>
        <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
        <!-- 是否有边框 -->
        <init-param>
            <param-name>kaptcha.border</param-name>
            <param-value>no</param-value>
        </init-param>
        <!-- 字体颜色 -->
        <init-param>
            <param-name>kaptcha.textproducer.font.color</param-name>
            <param-value>red</param-value>
        </init-param>
        <!-- 图片宽度 -->
        <init-param>
            <param-name>kaptcha.image.width</param-name>
            <param-value>135</param-value>
        </init-param>
        <!-- 图片高度 -->
        <init-param>
            <param-name>kaptcha.image.height</param-name>
            <param-value>50</param-value>
        </init-param>
        <!-- 使用哪些字符生成验证码 -->
        <init-param>
            <param-name>kaptcha.textproducer.char.string</param-name>
            <param-value>ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012345679
            </param-value>
        </init-param>
        <!-- 字符个数 -->
        <init-param>
            <param-name>kaptcha.textproducer.char.length</param-name>
            <param-value>4</param-value>
        </init-param>
        <!-- 字体大小 -->
        <init-param>
            <param-name>kaptcha.textproducer.font.size</param-name>
            <param-value>43</param-value>
        </init-param>
        <!-- 干扰线的颜色 -->
        <init-param>
            <param-name>kaptcha.noise.color</param-name>
            <param-value>black</param-value>
        </init-param>
        <!-- 使用哪些字体 -->
        <init-param>
            <param-name>kaptcha.textproducer.font.names</param-name>
            <param-value>Arial</param-value>
        </init-param>
    </servlet>

    <!--====================== 映射kaptcha验证码的url ======================== -->
    <servlet-mapping>
        <servlet-name>kaptchaCode</servlet-name>
        <url-pattern>/verifyCode.jpg</url-pattern>
    </servlet-mapping>
</web-app>