Provide pluggable filters to conduct necessary pre-processing and post-processing to requests from a client to a target

Use the Intercepting Filter pattern when

• a system uses pre-processing or post-processing requests
• a system should do the authentication/ authorization/ logging or tracking of request and then pass the requests to corresponding handlers
• you want a modular approach to configuring pre-processing and post-processing schemes

• Introduction to Intercepting Filter Pattern in Java

• javax.servlet.FilterChain and javax.servlet.Filter
• Struts 2 - Interceptors

• TutorialsPoint - Intercepting Filter