Issue
Can someone explain the difference between a servlet filter and tomcat valve. What is the advantage of using one over the other?
Solution
From Tomcat documentation:
A Valve element represents a component that will be inserted into the request processing pipeline for the associated Catalina container
The servlet filters serve the exact same purpose, but valves are Tomcat's specific classes, tightly coupled to Tomcat infrastructure/API. On the other hand servlet API is implemented by all compatible web containers. That said, valves won't work with e.g. Jetty, which has different API for that, while servlet filters will.
The other important difference is that valves are working on container level (intercepting all applications/requests), while servlet filters are intercepting all request only to a given application. So if you want to implement server-wide interceptor, valves are necessary.
Answered By - Tomasz Nurkiewicz
