Handling custom error pages - struts 2

When you work with struts 2, you may need to handle exception and
forward it to a custom error pages as you wish. The exception interceptor of struts 2 will catch exception and map them to user-defined error pages by type. For example, suppose you want to map all java.lang.Exception to a custom error page defined by yourself, you have to involve the exception interceptor.
You can add the fallowing entry to your struts.xml file just after the package element.

<global-results>
     <result name="error">/WEB-INF/jsp/errorPage.jsp
     </result>
</global-results>
<global-exception-mappings>
     <exception-mapping exception="java.lang.Exception" result="error" />
</global-exception-mappings>

With this declaration, each java.lang.Exception exception will end up with your error page. Also you can display more details on error in your custom page.Before yielding control to the result, the exception interceptor will create an ExceptionHolder object and place it on top of the ValueStack. The Exception-Holder is a wrapper around an exception that exposes the stack trace and the exception as JavaBeans properties that you can access from a tag in your error page. The following snippet shows our error JSP page:

Exception Name: <s:property value="exception" />

What you did wrong:<s:property value="exceptionStack" />

We can use the exception and exceptionStack property which are already exposed to ValueStack by ExceptionHolder object to get the details about the exception into the error page.