请问struts2 org.apache.struts2.dispatcher.ActionContextCleanUp有何用
<? xml version="1.0" encoding="UTF-8" ?>
< web-app id ="WebApp_9" 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 > Struts 2 Fileupload </ display-name >
< filter >
< filter-name > struts-cleanup </ filter-name >
< filter-class >
org.apache.struts2.dispatcher.ActionContextCleanUp
</ filter-class >
</ filter >
< filter >
< filter-name > struts2 </ filter-name >
< filter-class >
org.apache.struts2.dispatcher.FilterDispatcher
</ filter-class >
</ filter >
< filter-mapping >
< filter-name > struts-cleanup </ filter-name >
< url-pattern > /* </ url-pattern >
</ filter-mapping >
< filter-mapping >
< filter-name > struts2 </ filter-name >
< url-pattern > /* </ url-pattern >
</ filter-mapping >
< welcome-file-list >
< welcome-file > index.html </ welcome-file >
</ welcome-file-list >
</ web-app >
------解决方案--------------------
ctionContextCleanUp 清除Stack Context和ValueStack中的值
过滤器顺序：
（1）ActionContextCleanUp过滤器。
（2）SiteMesh核心过滤器。
（3）FilterDispatcher过滤器。