FAQ

My persisted model is stored in a Tinkergraph file instead of Neo4j

NeoEMF Blueprints connector uses the Tinkergraph representation as its default serialization mechanism. To enable Neo4j-based storage you need to provide a specific option to the Resource#save() method using the dedicated BlueprintsNeo4jConfig:

resource.save(new BlueprintsNeo4jConfig().asMap());

Note that this builder can be used to set Blueprints generic options as well as Neo4j specific options.

Can I use my existing database in NeoEMF?

Yes, you can save and load a NeoEMF model in your database by specifying its path in the URI used to create a resource:

Resource resource = resourceSet.createResource(<uri_to_my_database>);

Please note that your database has to be supported by NeoEMF. Existing non-modeling data (such as your own application data, manually stored information, etc) will not be accessible through the NeoEMF API.

WARNING: Using an existing database with the Blueprints-Neo4j connector will lock the database and reject any new connection. This is caused by the embedded Neo4j instance that allows only one connection per database.

Does NeoEMF support remote Neo4j database?

Not for now, the Blueprints-Neo4j connector uses an embedded Neo4j instance to save models that cannot be accessed and set by the client application. Since we received several questions related to this feature we put it on top of our backend integration todo list!

I get an UnsupportedOperationException when I save a model

NeoEMF is designed to be compatible with existing generated EMF code. However, the adapter which is in charge of the transformation from standard EMF objects to NeoEMF objects has not been implemented yet and an UnsupportedOperationException is thrown. A workaround is to create a new EMF Generator Model using NeoEMF importer and generate the code from it. The adapter implementation will be part of a next release.

I get NoSuchMethodError from Guava

The current version of NeoEMF relies on Guava 15 to be compatible with HBase. If you use a newer version of Guava in your project you may get NoSuchMethodErrors from NeoEMF or one of its components. We recommend to downgrade your Guava version if possible.

Note that the next major release of NeoEMF (1.1.0) will not depend on Guava and will be compatible with any Guava version used in your client application.