struts2 simple program, but Error 500--Internal Server Error

I am getting this as an output when I run my application
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Error 500--Internal Server Error
The Struts dispatcher cannot be found. This is usually caused by using Struts tags without the associated filter. Struts tags are only usable when the request has passed through its servlet filter, which initializes the Struts dispatcher needed for this tag. - [unknown location]
at org.apache.struts2.views.jsp.TagUtils.getStack(TagUtils.java:60)
at org.apache.struts2.views.jsp.StrutsBodyTagSupport.getStack(StrutsBodyTagSupport.java:44)
at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:48)
at jsp_servlet.__index._jsp__tag0(__index.java:113)
at jsp_servlet.__index._jspService(__index.java:84)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
at weblogic.servlet.internal.ServletStubImpl.onAddToMapException(ServletStubImpl.java:408)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:318)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3591)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2202)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2108)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1432)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)

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Hello.java :-

index.jsp

success.jsp

Hello-Validation.xml

web.xml

struts.xml

Directory Structure:-

Any kind of help will be appreciated.

@ Admin

Delete the post but anyways I am sharing the solution here:

I have fixed the problem,

solution is to use correct jar files, I was using ognl-3.0 , so when I switched to ognl-2.7.3 & also added javassist.jar it worked.

@heat rs,

I have fixed the problem,

solution is to use correct jar files, I was using ognl-3.0 , so when I switched to ognl-2.7.3 & also added javassist.jar it worked.

Thanks a lot..........
This post helps me a lot. I was suffering with this problem from last 2 days..
Thanks...........