In eclipselink, one can use a feature called copygroup, which is basically a concept similar to the entitygraph of jpa 2.1 by which one can obtain, copies of entities specifying which attributes and relationships of the entity graph can be copied.
https://wiki.eclipse.org/EclipseLink/Examples/JPA/AttributeGroup#Copy_Examples
is there a feature in hibernate that allows partial copying of entity object graphs using a copygroup / entity graph?
JPA 2.2 doesn't exist. JPA 2.1 provides Entity graphs, and that is available in ANY JPA 2.1 implementation (DataNucleus 3.3+, EclipseLink 2.5+, Hibernate 4.3+). That is the whole point of having something in a spec
Related
Is there a java framework which given a class with data members (including objects like arraylists) will create a table in a given database and be able to insert and select these entities from said database? I know about ORMs which given a table and DTO can map rows to entities, but is there a framework which will create the tables for you as well?
Comparing two of the most popular open source persistence frameworks, iBATIS and Hibernate by RedHat. We have something called Java Persistence API (JPA) and JPA2 by Sun-Oracle.
JPA itself has features that will make up for a standard ORM framework. That said you can use JPA alone in a project.
Hibernate is the most popular ORM framework, once the JPA got introduced hibernate conforms to the JPA specifications. Apart from the basic set of specification that it should follow hibernate provides whole lot of additional stuff.
I have been looking at Hibernate Envers for entity auditing. I'm using EclipseLink but I'd like something similar.
I've seen some implementations that involve creating a SessionCustomizer to handle some of the persistence of auditing data. I'd really like something like Hibernate where I can simply annotate the entity and have the same effect.
Unfortunately, EclipseLink doesn't have a feature which covers auditing out-of-the-box.
We use a SessionEventListener to intercept a flush or commit and use the calculated changeset for inserting the auditing data into audit tables.
There is support for auditing of entities in EclipseLink. They call it History.
http://wiki.eclipse.org/EclipseLink/Examples/JPA/History
This is a follow-up to
Limitation of JPA 1.0 using #IdClass with *nested* composite primary keys?
EclipseLink comes with a javax.persistence_1.0.0.jar which I also put onto the classpath, so it can know about the version of my entity classes. But how does Hibernate know the entity classes are meant to be in JPA 1.0? Can it be done? If so, how?
But how does Hibernate know the entity classes are meant to be in JPA 1.0?
If this can be done, I would bet on the version of the persistence.xml. But I'm really not sure this actually restricts the use of JPA 2.0 features.
Why not using a JPA 1.0 implementation if you want to be sure that you're not using anything from JPA 2.0 (i.e Hibernate EntityManager 3.4 in the case of Hibernate)? Is there anything that prevent you from doing so?
I'm trying to find a way to accomplish a xsd schema to datastore roundtrip, with minimum effort.
I used jaxb to build my object model from schemas, now I would like to store these objects based on JPA (or JDO or something else?). Is it possible, to auto enhance the objects with the missing annotations based on the JAXB Annotations? Is it desirable?
Thanks
You have several options for this use case.
Option #1 - Hyperjaxb3
I have not used this myself, but Hyperjaxb3 is supposed to generate both JAXB and JPA annotations on the model:
http://confluence.highsource.org/display/HJ3/Home
Option #2 - Use Dali to map your POJOs to Database (JPA)
The Eclipse Dali tool provides tooling to easily map your POJOs to a relational database using JPA:
http://www.eclipse.org/webtools/dali/
Option #3 - Use EclipseLink
EclipseLink provides both JPA and JAXB implementations. The JAXB implementation (MOXy) contains extensions specifically for handling JPA entities:
http://wiki.eclipse.org/EclipseLink/Examples/MOXy/JPA
Use DataNucleus and you can persist via JDO or JPA and internally it uses JAXB.
http://www.datanucleus.org
I learnt JPA for ORM. Now I am asked to use Hibernate as my provider.
If I start with Hibernate it is going down in different concept.
Please say me How can I relate JPA and hibernate together.
JPA reduces my Java code into simple code for persisting Objects.
Now what does hibernate help JPA and what does it provide.
Anyone please explain in simple.
As Pascal answered here
JPA is just an API. To use JPA, you need an implementation of this API and such implementations are called persistence providers (EcliseLink, Hibernate, OpenJPA)
Hibernate is not another concept; it is just one of many JPA implementations. Another would be EclipseLink. If you and the implementations keep to the specification then switching the implementation is just a matter of changing a couple of lines in your persistence.xml (e.g. the <provider> tag and implementation specific properties). At least in theory...
JPA is an API specification for persisting objects. It defines a SQL like query language, and annotations for defining entities and relationships.
Hibernate is an implementation of JPA that has various extensions as well as a legacy API and query language. As long as you don't use any of the extensions of Hibernate and stick with the JPA API you can more or less treat it interchangeably with other JPA implementations such as OpenJPA, TopLink etc.