---
layout: pattern
title: Intercepting Filter
folder: intercepting-filter
permalink: /patterns/intercepting-filter/
categories: pattern_cat
tags: pattern_tag
---

**Intent:** Provide pluggable filters to conduct necessary pre-processing and
post-processing to requests from a client to a target
 
![alt text](./etc/intercepting-filter.png "Intercepting Filter")
 
**Applicability:** 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