完整的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">
  <display-name>web.xml 的示例</display-name>
 
  <description>这是一个web.xml的示例。</description>
 
  <!-- 过滤器 -->
 
  <filter>
      <filter-name>logFilter</filter-name>
      <filter-class>com.gd.log.LogFilter</filter-class>
  </filter>
 
  <!-- 拦截所有以do 结尾的请求 -->
  <filter-mapping>
      <filter-name>LogFilter</filter-name>
      <url-pattern>*.do</url-pattern>
  </filter-mapping>
  <servlet>
      <servlet-name>dispatcherServlet</servlet-name>
      <servlet-class>com.gc.action.GcServlet</servlet-class>
      <!-- 初始化参数 -->
      <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>/WEB-INF/config-servlet.xml</param-value>
      </init-param>
  </servlet>
 
  <!-- 拦截所有以do 结尾的请求 -->
  <servlet-mapping>
      <servlet-name>dispatcherServlet</servlet-name>
      <url-pattern>*.do</url-pattern>
      </servlet-mapping>
     
 <!-- 设定session 过期时间 -->
 
 <session-config>
     <session-timeout>30</session-timeout>
 </session-config>
 
 <!-- 默认欢迎页面 -->
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
 
  <!-- 自定义标签 -->
  <taglib>
      <taglib-uri>/spring</taglib-uri>
      <taglib-location>/WEB-INF/spring.tld</taglib-location>
  </taglib>
  <!-- 数据库连接池 -->
  <resource-ref>
      <description>数据库连接池</description>
      <res-ref-name>jdbc/db</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Contaioner</res-auth>
  </resource-ref>
 
  <!-- 配置安全权限 -->
 
  <security-constraint>
      <web-resource-collection>
          <web-resource-name>示例</web-resource-name>
          <url-pattern>*.do</url-pattern>
      </web-resource-collection>
      <auth-constraint>
          <role-name>guest</role-name>
      </auth-constraint>
  </security-constraint>
 
  <!-- 安全权限角色 -->
 
  <security-role>
      <description>权限安全描述</description>
       <role-name>guest</role-name>
  </security-role>
 
  <!-- 登录配置 -->
  <login-config>
      <auth-method>FORM</auth-method>
      <realm-name>登录入口</realm-name>
     
      <form-login-config>
          <form-login-page>/login.jsp</form-login-page>
          <form-error-page>/error.jsp</form-error-page>
      </form-login-config>
  </login-config>
</web-app>