新手程序员 2017.8.28.16:08

这是一个web.xml文件 的 详解  一般在项目运行时先加载web.xml文件 然后  如下 ：

<?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/j2ee" xmlns:jsp="http://java.sun.com/xml/ns/javaee/jsp" xmlns:web="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">
  <display-name>project-ssi2</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>    1         在这里加载spring容器
            classpath*:/configs/spring/applicationContext.xml,  
            classpath*:/configs/spring/applicationContext*.xml
        </param-value>
  </context-param>
  <welcome-file-list>    2 这里是欢迎界面 项目运行后的第一个页面
    <welcome-file>/modules/index.jsp</welcome-file>
  </welcome-file-list>
  <filter>      3 过滤器  这里是编码格式 过滤器
    <filter-name>encodingFilter</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>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <filter>     4 报表的 过滤器
    <filter-name>sitemesh</filter-name>
    <filter-class>org.sitemesh.config.ConfigurableSiteMeshFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>sitemesh</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <filter>
    <filter-name>struts2Filter</filter-name>
    <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>  5 这里是 struts2 的过滤器 将所有的 action 全都 在这里过滤通过
    <filter-name>struts2Filter</filter-name>
    <url-pattern>*.action</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
  </filter-mapping>
  <filter-mapping>
    <filter-name>struts2Filter</filter-name>
    <url-pattern>*.jsp</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>ERROR</dispatcher>
  </filter-mapping>
  <jsp-config>
    <taglib>
      <taglib-uri>http://jsptags.com/tags/navigation/pager</taglib-uri>
      <taglib-location>/WEB-INF/tags/pager-taglib.tld</taglib-location>
    </taglib>
  </jsp-config>
  <listener>  6 监听器 这里是最高权限的监听器
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <error-page>  7 错误的情况 。以及各个路径 。
    <exception-type>java.lang.Throwable</exception-type>
    <location>/modules/common/error/error.jsp</location>
  </error-page>
  <error-page>
    <error-code>500</error-code>
    <location>/modules/common/error/error.jsp</location>
  </error-page>
  <error-page>
    <error-code>404</error-code>
    <location>/modules/common/error/error_404.jsp</location>
  </error-page>
  <error-page>
    <error-code>403</error-code>
    <location>/modules/common/error/error.jsp</location>
  </error-page>
</web-app>