EMF/Teneo 1.0.4/EclipseLink Support

Teneo 1.0.4 provides support for EclipseLink. The following sections explain the principal features it includes and give advice how they can be used for building model-based applications on top of relational databases.

Creating EclipseLink/JPA Mappings for EMF models

Three possibilities:

• Model-driven
• Meet-in-the-middle
• Schema-driven

Accessing EMF Models in Databases using the EclipseLink Resource

Teneo/EclipseLink provides a full implementation of EMF's Resource interface named EclipseLinkResourceImpl. It enables applications to load and save EMF models from or to relational databases and to manage their lifecycle directly through EMF's built-in persistence API, i.e. the ResourceSet interface. EclipseLinkResourceImpl represents an almost complete abstraction from JPA mappings and EclipseLink APIs and makes accessing models in databases, from an EMF point of view, as natural as loading or saving models from files.

Along with EclipseLinkResourceImpl a dedicated eclipselink URI protocol and a underlying resource factory named EclipseLinkResourceFactoryImpl have been defined. EclipseLink URIs enable models in databases to be referenced and the EclipseLink resource factory makes sure that instances of EclipseLinkResourceImpl are used to load and save such models.

 // create EclipseLink URI for saving/loading library model in/from database
 String query = EclipseLinkResourceUtil.createContentsEqualQuery(LibraryPackage.eINSTANCE.getLibrary(),LibraryPackage.eINSTANCE.getLibrary_Name(), library1.getName());
 uri = EclipseLinkResourceUtil.createEclipseLinkURI(TEST_PERSISTENCE_UNIT_NAME, query);

 // save library model instance in database
 ResourceSet resourceSet1 = new ResourceSetImpl();
 resourceSet1.getLoadOptions().putAll(getTestPersistenceUnitProperties());
 resource1 = resourceSet1.createResource(uri);

 assertTrue(resource1 instanceof EclipseLinkResourceImpl);
 assertFalse(resource1.isLoaded());

 resource1.getContents().add(library1);

 assertTrue(resource1.isLoaded());

 resource1.save(Collections.EMPTY_MAP);

Building Model-based Rich Client Applications on top of Teneo and EclipseLink

--Stephaneberle9.gmail.com 05:16, 16 March 2009 (UTC)