首先，web.xml中需要配置的哪些东西？
1.配置监听器<listener>
它有两个监听器：
1).
<!--配置文件加载监听器-->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
ContextLoaderListener它的作用是启动web容器，(加载配置文件)自动装配applicationContext.xml配置信息(详细配置见下面)。
2).
<!--spring log4j日志监听器配置-->
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
<context-param>
<param-name>Log4jConfigListener</param-name>
<!-- 配置文件的位置 -->
<param-value>classpath:log4j.properties</param-value>
</context-param>
<context-param>
<param-name>Log4jConfigListener</param-name>
<!-- spring刷新log4j文件的时间间隔 -->
<param-value>10000</param-value>
</context-param>
2.部署applicationContext.xml文件
如果不写任何参数配置，默认的是在/WEB-INF/applicationContext.xml
如果想要自定义文件名，需要在web.xml中加入contextConfigLocation这个context参数
<!-- 配置applicationContext.xml -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext*.xml</param-value>
</context-param>
3.配置前端控制器DispatcherServlet:它是拦截请
<!-- 配置DispatchServlet 的核心控制器 -->
DispatchServlet是HTTP请求的*调度处理器，它将web请求转发给controller层处理，它提供了敏捷的映射和异常处理机制。
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>或者：
applicationContext.xml配置文件还可以使用<init-param>标签在servlet标签中进行配置
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!-- 初始化applicationContext.xml -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</init-param></servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
4.<!-- 错误跳转页面 -->
<error-page>
<!-- 路径不正确 -->
<error-code>404</error-code>
<location>/WEB-INF/errorpage/404.jsp</location>
</error-page>
<error-page>
<!-- 没有访问权限，访问被禁止 -->
<error-code>405</error-code>
<location>/WEB-INF/errorpage/405.jsp</location>
</error-page>
<error-page>
<!-- 内部错误 -->
<error-code>500</error-code>
<location>/WEB-INF/errorpage/500.jsp</location>
</error-page>5.配置字符集编码
<filter>
<!-- 用来对浏览器的每一次请求进行过滤，加上了父类没有的功能，就是设置字符集编码
，一般只用来配置字符集 -->
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
<init-param>
<!-- forceEncoding用来设置是否理会 request.getCharacterEncoding的方法 -->
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>以上就是我们经常会用到的东西。
《*****************************下面贴上一个完整的示例：********************************》
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<display-name>Web Application</display-name><!-- 读取spring配置文件 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/spring/applicationContext*.xml</param-value>
</context-param>
<!-- Spring字符集过滤器 -->
<filter>
<filter-name>SpringEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>SpringEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
<filter-name>springSessionRepositoryFilter</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>springSessionRepositoryFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- spring log4j监听器配置 日志记录 -->
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:log4j.properties</param-value>
</context-param>
<context-param>
<param-name>log4jRefreshInterval</param-name>
<param-value>60000</param-value>
</context-param><listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener><listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>
<!-- springMVC核心配置 -->
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<!-- 注解式控制器 -->
<param-name>dispatchOptionsRequest</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>dispatchTraceRequest</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/spring/applicationContext-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list><!-- 错误跳转页面 -->
<error-page>
<!-- 路径不正确 -->
<error-code>404</error-code>
<location>/WEB-INF/errorpage/404.jsp</location>
</error-page>
<error-page>
<!-- 没有访问权限，访问被禁止 -->
<error-code>405</error-code>
<location>/WEB-INF/errorpage/405.jsp</location>
</error-page>
<error-page>
<!-- 内部错误 -->
<error-code>500</error-code>
<location>/WEB-INF/errorpage/500.jsp</location>
</error-page>
</web-app>