Difference between JPA Entity and Hibernate Entity

Question

When I annotate a class with @Entity and try to resolve the dependencies, I get to choose the package between two different packages, javax.persistence.Entity and org.hibernate.annotations.Entity

The javax package is JPA's entity-annotation, but why is there a hibernate entity-annotation and difference does it have with JPA's annotation? Is it just an extension to allow more attributes to be defined?

Answer 1

I'm not sure about the differences but I am sure that if you have the Hibernate jars in your classpath you are using Hibernate JPA. Hibernate provides an implementation of JPA. Even though you are using the javax.persistence package you are using Hibernate JPA.

The difference could be only in the naming. They might provide the same classes both in the Hibernate package space and the javax package space.

Answer 2

org.hibernate.annotations.Entity has some extra attributes that javax.persistence.Entity has not standarized. The extra features will only work if using hibernate's AnnotationConfiguration directly or if hibernate is the JPA provider.

from the FAQ:

I use @org.hibernate.annotations.Entity and get an Unknown entity exception

Always import @javax.persistence.Entity

@org.hibernate.annotations.Entity completes @javax.persistence.Entity but is not a replacement

For instance, there is an attribute called optimisticLock, which tells hibernate whether to use the standard version column or to compare all columns when updating. This behavior is not in the JPA spec, so in order to configure it, you must use hibernate specific extension found in their own annotation.

Like this:

@Entity
@org.hibernate.annotations.Entity(optimisticLock=OptimisticLockType.ALL)
public class MyEntity implements Serializable {
...
}