About Metadata API

manual

JPA Metamodel API

Explains how to use the JPA Metamodel API to retrieve details on the types and attributes of the persistent object model. The JPA Metamodel API provides the ability to examine the persistent object model and retrieve ... Interface The main interface of the JPA Metamodel API is Metamodel javax.persistence.metamodel.Metamodel JPA ... Hierarchy Types are represented in the Metamodel API by descendant interfaces of the Type ...

 
api-jdo

javax.jdo.Constants

Constant values used in JDO.(Interface of JDO)

 
forum_thread

JDO support vs JPA

Hi, I am about to update the JDO metadata in the package.jdo files after moving from ObjectDB 1 to 2. However I found that there is no complete description or guide how the XML metadata should look in version 2. I found only small fragments of attributes in the description of JDO Annotations (to which XML element is the given annotation equivalent). So my questions to this are: 1. Is there some description of XML metadata for ObjectDB ver2 using JDO which I did not find? ... Hi, I am about to update the JDO metadata in the package.jdo files after moving from ObjectDB 1 to 2. However I ... either this or that ? 3. I found there is only API documentation for JDO and no manual at all as there is for JPA. Does this ...

 
forum_thread

Indexing a field results in internal Exception

I have an application that I have been converting from JPA/MySQL to JDO/ObjectDB and I have hit a problem with indexing. An index on a String field is required to give good performance but if I add the @Index annotation to the field I eventually end up with an ObjectDB internal exception.  This is reproducible, as is the program running to completion (slowly) if I remove the @Index annotation.  Is there anything I can look for that might result in this exception? ... I have long been a fan of JDO as it's a hugely easer API and gets work done with a lot less metadata.  edit ...

 
api-jpa

javax.persistence.EntityManager

Interface used to interact with the persistence context.(Interface of JPA)

 
forum_thread

mapping file is not being loaded

Hi, I am evaluating ObjectDB by using it with an in-house developed library in order to prototype its capabilities / performance. I am having a problem in that the in-house library in question reads a simple configuration file to determine available persistence units, and then bootstraps them using the JPA Persistance.createEntityManagerFactory() method and passing in the persistence unit name (again, obtained from the configuration file ). ... the java code that interacts with the Persistence api: EntityManagerFactory emf = Persistence . ... back to false, and ran the original project.  The metadata was now accessible. So it appears then that Metamodel for a ...

 
forum_thread

Class fields selection to store

In a class how do I define which are the fields to be stored? (using JDO API) It's using persistence-modifier="persistent" ? If I have a class with 40 fields and I only want to store one of the fields should I do the following? <class name="Car">    <field name="Wheels" persistence-modifier="persistent" /> </class> Which are the value used for fields that I do not want to store? ... do I define which are the fields to be stored? (using JDO API) It's using persistence-modifier="persistent" ? If ... JDO 2.1 you can use annotations instead of XML metadata). ObjectDB Support ObjectDB - Fast ...

 
forum_thread

How to define Default Entity Listeners without persistence.xml and orm.xml

I am using JPA programaticaly..ie without xml file, and i would like to define Default Entity Listeners. How to do ? Here my init code: ... is one of the few things that currently require XML metadata. You cannot define default listeners using annotations (at ... a way using em.getDelegate() and then using objectdb api ? I would like to do specifics actions when my objects are ...