Question

I would like to manage requests. Exactly I want delay response for some requests by passing it to queue and next handle it using other thread. I’m using servlet’s filter. In doFilter method I don’t call filterChain’s doFilter and in spite of this the response is sent. In other thread I’m getting null when I call this method on filterChain from my queue.

What is wrong in these 2 issues (don’t send response immediately?

Answer 1

You are not supposed to do that. Request and Response object scope is valid only inside Servlet's service() and Filter's doFilter() methods invoked as part of container dispatch.

Servlet Spec Says……

Containers commonly recycle response complete method on objects in order to avoid the performance overhead of response object creation. The developer must be aware that maintaining references to response objects for which startAsync on the corresponding request has not been called, outside the scope described above may lead to non-deterministic behavior.

Note: You should be using Servlet 3.0 Asynchronous Request Processing through which request can be suspended and resumed.