The relationship between Hibernate and JPA

JPA Full name Java Persistence API. JPA describes the mapping of objects-relational tables through JDK 5.0 annotations or XML, and persists entity objects for the run-time into the database.

The overall idea of JPA is broadly consistent with existing ORM frameworks such as Hibernate, TopLink, JDO, and so on. In general, JPA includes the following 3 areas of technology: ORM Mapping Meta dataJPA supports both XML and JDK5.0 annotations in the form of metadata that describes the mapping between objects and tables, in which the framework persists entity objects into database tables; APIFor manipulating entity objects, performing CRUD operations, the framework does everything for us in the background, and developers are freed from tedious JDBC and SQL code. Query LanguageThis is an important aspect of persistent operations, querying data through object-oriented rather than database-oriented query language to avoid tightly coupling the SQL statements of the program.

I know that JPA is a specification, and hibernate is an implementation of it. In addition to hibernate, there are Eclipselink (formerly TopLink), OPENJPA, etc. to choose from, so one advantage of using JPA is that you can replace the implementation without having to change too much code.

When you define the model in play, you use the JPA annotations, such as Javax.persistence.Entity, Table, Column, Onetomany, and so on. But they provide the functional basis, sometimes want to define the finer, will inevitably use hibernate itself annotation. I thought that JPA was so weak to use it for, why not use hibernate directly? Anyway, I'm not going to replace it with another implementation.

Because I quickly decided not to use Hibernate, this problem has been put down. Until I'm in the new company, I'm going to use hibernate for the project.

I wanted to put aside JPA and use hibernate annotations directly to define the model, and soon found several problems:

1. There are entity in JPA, but there are table,hibernate, but the content is different.
2. There are column,onetomany in JPA, not in Hibernate, no substitutes.

I thought hibernate's support for JPA was another set of annotations that were dedicated to JPA, but it doesn't seem to be. Some important annotations such as column, Onetomany, and Hibernate are not available, which means that the JPA annotations are already at the heart of Hibernate, and Hibernate provides only a few additions, not two sets of annotations. If so, hibernate's support for JPA is really sufficient, and we will use the Hibernate annotations to make sure that JPA is used.

Is that the situation? In the group (Scala Communication group 132569382) Friends despise but did not give a satisfactory answer, I think of the Almighty StackOverflow, up to mention two asked:

1. Http://stackoverflow.com/questions/8306742/if-i-want-to-use-hibernate-with-annotation-do-i-have-to-use-javax-persistence
2. Http://stackoverflow.com/questions/8306793/why-jpa-and-hibernate-both-have-entity-and-table-annotations

The first one is asking if you want to use Hibernate to annotate, is it sure to use JPA. Netizen's answer: "Yes." If hibernate thinks the JPA annotations are sufficient, it is used directly. Or you'll get a self-made supplement. "

The second question is, JPA and hibernate provide the entity, which one should we use, or can we use two together? The netizen replied that "Hibernate's entity is inherited from JPA, so if you feel that JPA is not enough, use hibernate directly."

The relationship between Hibernate and JPA