>>> FilterDispatcher <<< is deprecated! Please use the new filters!

在struts2.3.20下，web.xml中使用

会出现
***********************************************************************
*                               WARNING!!!                            *
*                                                                     *
* >>> FilterDispatcher <<< is deprecated! Please use the new filters! *
*                                                                     *
*           This can be a source of unpredictable problems!           *
*                                                                     *
*              Please refer to the docs for more details!             *
*            http://struts.apache.org/2.x/docs/webxml.html            *
*                                                                     *
***********************************************************************
原因在于:

Class FilterDispatcher

Deprecated. Since Struts 2.1.3, use StrutsPrepareAndExecuteFilter instead or StrutsPrepareFilterand StrutsExecuteFilter if needing using the ActionContextCleanUp filter in addition to this one

从>=2.1.3的版本开始，FilterDispatcher被标记为过时，取而代之的是新的

StrutsPrepareAndExecuteFilter

所以如果你的struts版本大于2.1.3时，filter配置要变成：

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

解决方法，将web.xml上述代码改为：

<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
</filter-class>
</filter>

<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>