What are the key components of persistence API in EJB?

1.	What are the key components of persistence API in EJB?
Answer» Following are the key components of persistence API in EJB: Entity - A persistent object representing the data-store record. It is good to be serializable. EntityManager - Persistence interface to do data operations like add/delete/update/find on persistent object(entity). It also helps to execute queries using Query interface. Persistence unit (persistence.xml) - Persistence unit describes the properties of persistence mechanism. *Data Source (ds.xml)** - Data Source describes the data-store related properties like connection url. user-name,password etc.

Answer»

Following are the key components of persistence API in EJB:

Entity - A persistent object representing the data-store record. It is good to be serializable.
EntityManager - Persistence interface to do data operations like add/delete/update/find on persistent object(entity). It also helps to execute queries using Query interface.
Persistence unit (persistence.xml) - Persistence unit describes the properties of persistence mechanism.
Data Source (*ds.xml) - Data Source describes the data-store related properties like connection url. user-name,password etc.

Discussion