How to configure struts2 in Eclipse: classnotfoundexception: org... Dispatcher. Ng. Filter. strutsprepareandexecutefil

In the beginning, I configured user libraries (Struts-2.2.3 for multiple projects) according to a textbook ), then introduce Struts-2.2.3 directly (this package will not be placed in the project folder ):

However, the program cannot be started due to an error as shown in the following figure:

Severe: exception starting filter struts2
Java. Lang. classnotfoundexception: org. Apache. struts2.dispatcher. Ng. Filter. strutsprepareandexecutefilter
At org. Apache. Catalina. loader. webappclassloader. loadclass (webappclassloader. Java: 1680)
At org. Apache. Catalina. loader. webappclassloader. loadclass (webappclassloader. Java: 1526)
At org. Apache. Catalina. Core. applicationfilterconfig. getfilter (applicationfilterconfig. Java: 269)
At org. Apache. Catalina. Core. applicationfilterconfig. setfilterdef (applicationfilterconfig. Java: 422)
At org. Apache. Catalina. Core. applicationfilterconfig. <init> (applicationfilterconfig. Java: 115)
At org. Apache. Catalina. Core. standardcontext. filterstart (standardcontext. Java: 4071)
At org. Apache. Catalina. Core. standardcontext. Start (standardcontext. Java: 4725)
At org. Apache. Catalina. Core. containerbase. Start (containerbase. Java: 1053)
At org. Apache. Catalina. Core. standardhost. Start (standardhost. Java: 840)
At org. Apache. Catalina. Core. containerbase. Start (containerbase. Java: 1053)
At org. Apache. Catalina. Core. standardengine. Start (standardengine. Java: 463)
At org. Apache. Catalina. Core. standardservice. Start (standardservice. Java: 525)
At org. Apache. Catalina. Core. standardserver. Start (standardserver. Java: 754)
At org. Apache. Catalina. startup. Catalina. Start (Catalina. Java: 595)
At sun. Reflect. nativemethodaccessorimpl. invoke0 (native method)
At sun. Reflect. nativemethodaccessorimpl. Invoke (nativemethodaccessorimpl. Java: 39)
At sun. Reflect. delegatingmethodaccessorimpl. Invoke (delegatingmethodaccessorimpl. Java: 25)
At java. Lang. Reflect. method. Invoke (method. Java: 597)
At org. Apache. Catalina. startup. Bootstrap. Start (Bootstrap. Java: 289)
At org. Apache. Catalina. startup. Bootstrap. Main (Bootstrap. Java: 414)

A bit of Baidu in Google, there is no effective solution. According to the error message, the org. Apache. struts2.dispatcher. Ng. Filter. strutsprepareandexecutefilter class cannot be found. However, I did find this class manually:

To ensure that the class name is not spelled correctly, right-click the strutsprepareandexecutefilter. class file, select "Copy qualified name" (copy the exact name), and paste it to the Web. save and re-run the XML file. The same error occurs, proving that the class name is not spelled correctly.

Finally, I abandoned user libraries and manually copied the related jar of struts2 to the/webcontent/WEB-INF/lib directory:

Run the program again!

That is to say, Tomcat loads resources from the WEB-INF/directory by default, eclipse in the release of the program, the related resources of user libraries are not copied to the WEB-INF/directory (eclipse will put all the non *. java file to the WEB-INF/classes directory), so Tomcat says it cannot find the required class.

Note:

Tool version:

Tomcat: 6.0.32

Eclipse Java EE: 3.6.2

Struts2: 2.2.3

Tool: QQ

Image editing: mspaint