配置struts-2.5.16必需jar包Struts2的特性变动

if you are using struts2 version 2.5 you need to change from 

org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter 

to

org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter

<?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" 
　　　　　xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
　　　　　xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  
<filter>
    <filter-name>struts2</filter-name>
    <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
　　"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
　　"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

</struts>