在Eclipse IDE進行Struts開發時提示錯誤：java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.FilterDi

If you have...

1. included all necessary jars
2. Configured build path correctly
3. added them all in deployment assembly
   Correctly.

then also you getting "java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.FilterDispatcher" error then you could be doing below things wrong.

solution:

check your struts2-core-x.x.jar version.

-->if it is struts2-core-2.5.jar then change your filter class tag value in web.xml to

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

-->if it is struts2-core-2.1.3.jar then change your filter class tag value in web.xml to

<filter-class>
     org.apache.struts2.dispatcher.FilterDispatcher
</filter-class>

FilterDispatcher is deprecated since Struts 2.1.3. If you are working with older versions then user above solution.

-->if it is struts2-core-2.3.X.jar then change your filter class tag value in web.xml to

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

Reason behind all this is struts 2 controllers are placed in different location in different version of struts2-core jar and some time they are called by different name as you can see in 2.1.3.

Thank you!

須要注意的是：

　　在struts2.1版本以前，所使用的核心過濾器類是 org.apache.struts2.dispatcher.FilterDispatcher，從struts2.1版本以後，已經不推薦使用，而是使用org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter類。可是當struts版本發展到2.5以後的版本時，推薦將類徹底名稱中的ng去掉，即便用org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter類。