alo

April 05

Prof. Ismael H. F. Santos - ismael@tecgraf.puc-rio.br 2

Service Layer

• Where do we position loosely-coupled business logic? What is service logic?

• How should container level services be implemented?

• How do we support transactions in a POJO based application?

• How do we communicate from our presentation layer to our persistence layer?

• How do we get to services that contain business logic?

• How should our business objects communicate with our persistence layer?

• How do we get objects retrieved from our persistence layer to our UI layer?


	There are typically four layers within a web container:
		A presentation layer that concentrates on request/response actions which handles UI. Typically uses an MVC framework.
		A business service layer to manage transactions and business logic. This is usually not addressed in many applications today or tightly coupled in an inappropriate layer.
		A persistence layer to communicate with a back-end relational database.
		A domain object model that can be used across all layers.