# Hooking into Java User Exits (interceptors)

Interceptors allow additional logic to be executed before or after the invocation of a service. To implement an interceptor:

- Identify the page to extend.
- Identify the interceptor interface to implement.
- Create an interceptor class.
- Code the desired logic into the interceptor class.
- Register the class in CMServiceConfig.xml.

Parent topic: Hooking into User Exits