The default request-response model offered in the JAX-RS implementation fits well for many common use cases. However, at times, you may look for extending the default request-response model. For instance, you may need such extension capabilities while adding support for the custom authentication, customized caching of responses, encoding request content, and so on, without polluting the application code. JAX-RS allows you to do this by adding your own interceptors and filters for both the REST requests and responses, as appropriate.

Typically, filters are used for processing the request-response headers, whereas interceptors are concerned with the marshalling and unmarshalling of the HTTP message bodies. Filters and interceptors can be set on both the client and the server. Let's learn more about these offerings in this section.