Filters vs Interceptors in Struts 2

Question

What\'s the difference, really, between filters and interceptors? I realize that interceptors fire before and after an action, recursively, and filters can be configured to fir

Answer 1

The most significant difference is that "interceptors" are a part of the Struts 2 framework, and are only part of the request handling that is done by the Struts 2 framework. "Filters" on the other hand are a part of the Servlet Specifcation; in other words, they are part of the Servlet API. If you are using Struts 2, you should use interceptors for wrapping functionality around your Struts 2 actions. If you are trying to wrap functionality around requests coming to your webapp, but not being handled by Struts 2, then a filter might be more appropriate.

BTW, the entire Struts 2 Framework is deployed inside a filter configured in your web app, declared in your webapp's deployment descriptor ( web.xml ) like:

    
        struts2
        org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
    

     
        struts2
        /*
    

This filter, which is configured to catch all requests URL patterns, is the entry point into the entire Struts 2 framework.

I hope that helps.