The two primary extension points are the interfaces: Filter (for processing a request and/or response en
route) and Handler (for generating responses from requests).
These interfaces are similar to the Java Enterprise Edition
Filter and Servlet interfaces, with
some differences in the semantics of messages. While you can simply implement
these interfaces, there are also included convenience classes: GenericFilter and GenericHandler that you can use if you intend to make
your extensions configurable through the OpenIG configuration
resource.
OpenIG also allows standard Java Enterprise Edition servlets and servlet filters to be embedded in the gateway, with initialization parameters supplied through through the OpenIG configuration resource.
