The previous chapter showed how to implement persistent objects using JPA and how to query them with JPQL. The persistence layer is developed using objects that encapsulate and map their attributes to a relational database, thanks to annotations. The idea is to keep the entities as transparent as possible and not intermingle them with business logic. Entities can have methods to validate their attributes, but they are not made to represent complex tasks, which often require an interaction with other components (other persistent objects, external services, etc.).


Business Logic Domain Name System Remote Method Invocation Java Messaging Service Remote Interface 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Antonio Goncalves 2009

Personalised recommendations