Struts2.0 have several advantages but also have some disadvantages.Strust is not easy to learn and it is used for larg project only.

 
Disadvantages of the Struts2 framework:

1.Need more Learning:- Struts2 is not for small project .As Struts2 need more learning any developer can not work on struts2 directly. Before work on struts2 developers must have knowledge of Core Java, JSP, Servlets, HTML, Custom JSP Tags, Tags library and also Struts2 need more clear knowledge of Struts2 frameworks also like is follow, working of different Action classes ,way of configuring XML file and plug-in etc .That mean any developer must need expertise before work on Struts2 application .but This is not an issue with experienced developers.

2. Not More Documentation:- As Compare Servelet, JSP struts2 have no more online free help materials. Only Apache has provided some help which is not sufficient and has note covers sufficient examples. So developer needs more works on study.

3. Less Transparent In a Struts applications:- In Struts2 there is a so many things are going on behind the scenes than with normal Java-based Web applications. 
As a result, Struts2 applications are: not easy to understand and not easy to benchmark and optimize.

4.Disadvantage Imposing :- You want to use Struts2 then you will have to just follow the rules set by this framework. 

5.Disadvantage Performance :-This frameworks  bigger call stacks due to various function calls which results in lesser performance.Convention problem:-The Struts2 framework more follow the convention.

6.Harder to learn:-Struts2 are harder to learn, benchmark and optimize.

7.Jar file required problem.

8.XML file configuration problem



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