HTTP protocol processor is a collection of protocol interceptors that implements the 'Chain of Responsibility' pattern, where each individual protocol interceptor is expected to work on a particular aspect of the HTTP protocol the interceptor is responsible for.

Usually the order in which interceptors are executed should not matter as long as they do not depend on a particular state of the execution context. If protocol interceptors have interdependencies and therefore must be executed in a particular order, they should be added to the protocol processor in the same sequence as their expected execution order.

Protocol interceptors must be implemented as thread-safe. Similarly to servlets, protocol interceptors should not use instance variables unless access to those variables is synchronized.