JPA Criteria Queries over RDF Data

We present the design and implementation of a prototype system for querying RDF data via the Java Persistence API (JPA) criteria query feature. The JPA is a specification for management of (primarily, but not limited to) relational data and provides a framework for uniform storage and retrieval of Java objects using various backends. The framework provides the Criteria API, which enables building queries programmatically against a Java domain model and executing them on any supported backend. In this short paper, we describe our work towards supporting the Web of Data as a new backend. Our contributions comprise (i) a system design for enabling JPA compliant object/RDF mappings together with de-/serialization of object graphs as RDF, (ii) an approach for rewriting criteria queries to SPARQL queries, and (iii) a prototype implementation.