maven-web-xml

首先，maven工程中的web.xml配置文件不是必须的。

<?xml version="1.0" encoding="UTF-8"?> //xml的版本号为1.0，字符编码为utf-8
    <web-app version="2.5" 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/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd http://java.sun.com/xml/ns/javaee ">
    /**
     * ContextLoaderListener加载内容
     * context-param用来声明应用范围(整个WEB项目)内的上下文初始化参数。
     * @param param-name 设定上下文的参数名称。必须是唯一名称
     * @param param-value  设定的参数名称的值
     */
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:application-context.xml</param-value> 
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    /**
     * DispatcherServlt加载内容
     * 
     */
    <servlet>
        <servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/servlet-context.xml</param-value>
        </init-param>
    <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>


    //指定欢迎页面(个人理解这不是首页吗，欢迎页其实我一点都不欢迎你来访问)
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>  //javaweb项目默认index.html是首页
        ......
        //可设置多个页面，从上往下，依次查找，找到就显示，结束这次任务
        <welcome-file>user/index.html</welcome-file>
        //可对不同的文件设置自身的首页
    </welcome-file-list>

    //错误编码，跳转自定义页面
    <error-page>
        <error-code>404</error-code>
        <location>/user/8888.html</location>
    </error-page>

    //抛异常
    <error-page>
        <exception-type>java.lang.Exception<exception-type>
        <location>/exception.html<location>
    </error-page>

    //过滤器解决spring编码问题，只对post请求有效
    <filter>
        <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>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
</web-app>