多选题

About the Filter and&n...

Question

About the Filter and Listener in J2EE Servlet ，Which of the following descriptions is correct: （多选）

A. Filter and Listener are all based on java reflection mechanism

B. We can use the filter to implement the user authentication

C. We can use the listener to integration with the 3-party framework &amp plugin in servlet container

D. Filter and listener all can be used to do character encoding conversion which from endpoint users