Apache Commons RDF (incubating)
Commons RDF has transitioned to the Apache Incubator, with an aim to become part of Apache Commons. This project was previously hosted at commons-rdf.github.io, which is not affiliated with the Apache Software Foundation.
Commons RDF aims to provide a common library for RDF 1.1 that could be implemented by systems on the Java Virtual Machine.
The main motivation behind this simple library is revise an historical incompatibility issue. This library does not pretend to be a generic api wrapping those libraries, but a set of interfaces for the RDF 1.1 concepts that can be used to expose common RDF-1.1 concepts using common Java interfaces. In the initial phase commons-rdf is focused on a subset of the core concepts defined by RDF-1.1 (URI/IRI, Blank Node, Literal, Triple, and Graph). In particular, commons RDF aims to provide a type-safe, non-general API that covers RDF 1.1. In a future phase we may define interfaces for Datasets and Quads.
The design of the API follows the terminology as defined by RDF 1.1 Concepts and Abstract Syntax, a W3C Recommendation published on 25 February 2014. The idea is that Commons RDF provide a common library for RDF 1.1 with multiple implementions for the Java Virtual Machine, allowing the portability across different Commons RDF implementations.
Commons RDF is designed for compatibility between different implementations, e.g. by defining strong equality and hash code semantics (e.g. for triple and literals ); this allows users of Commons RDF to “mix and match”, for instance querying a FooGraphImpl and directly adding its FooTripleImpls to a BarGraphImpl without any explicit convertion.
To create such instances without hard-coding an implementation, one can use:
The API also includes a couple of “upper” interfaces which do not have the above equality semantics and bridge the graph/quad duality:
See the the user guide for examples of how to interact with these interfaces.
The project is composed by two modules:
Both modules follow the semantic versioning principles, where version x.y.z of Simple implements version x.y of the API; i.e., the version z are backwards-compatible patches of the implementation.
Please, take into account that this library is still work in progress, this set of interfaces are still under discussion and evolution. Therefore everybody is welcomed to join the project and contribute!
Apache Commons RDF is an effort undergoing incubation at The Apache Software Foundation (ASF) sponsored by the Apache Incubator PMC. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.