Commons RDF

Working repository for experimenting with idea of providing a common library for RDF 1.1 that could be implemented by the upcoming versions of the main Java toolkits (Jena 3.0 and Sesame 4.0) as well as wrappers for other JVM languages (Banana RDF and so on).

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 (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.

Status

This library is still work in progress.

A draft diagram of the interfaces which may be included in Commons RDF are:

Building

Building has been tested with Apache Maven 3.2 and Java JDK 8.

$ mvn clean install
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO] 
[INFO] Commons RDF
[INFO] Commons RDF: API
[INFO] Commons RDF: Simple impl
[INFO] 
[INFO] Using the builder org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder with a thread count of 1
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Commons RDF 0.0.3-SNAPSHOT
    ....
[INFO] Installing /home/johndoe/src/commons-rdf/commons-rdf-api/target/commons-rdf-api-0.0.3-SNAPSHOT-javadoc.jar to /home/johndoe/.m2/repository/com/github/commons-rdf/commons-rdf-api/0.0.3-SNAPSHOT/commons-rdf-api-0.0.3-SNAPSHOT-javadoc.jar
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] Commons RDF ....................................... SUCCESS [  1.792 s]
[INFO] Commons RDF: API .................................. SUCCESS [  2.676 s]
[INFO] Commons RDF: Simple impl .......................... SUCCESS [  3.142 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.718 s
[INFO] Finished at: 2015-01-26T02:09:10+00:00
[INFO] Final Memory: 22M/309M
[INFO] ------------------------------------------------------------------------

To then use from your project, add to Maven (update <version> to match the Maven output):

<dependency>
    <groupId>com.github.commons-rdf</groupId>
    <artifactId>commons-rdf-api</artifactId>
    <version>0.0.3-SNAPSHOT</version>
</dependency>

Java 6/7 compatibility

This API is targeting Java 8, as Java 7 is scheduled EOL at April 2015.

For convenience, a patched edition for Java 6 and 7 is however available.

To build with Java 1.6/1.7 compatibility, use the java6 Maven profile:

$ mvn clean install -Pjava6

To then depend on the Java 6 edition in your Maven project, you need to use a special classifier to the dependency:

<classifier>java6</classifier>

Note that the Java 6 edition depends on the Guava libraries for providing the missing features. If you use the Java 6 version, your code will probably not be binary compatible with libraries compiled against the regular (Java 8) edition of the Commons RDF API.

The simple implementaton and testing (see below) are not included in the -Pjava6 edition.

Simple implementation

The commons-rdf-simple module contains a simple (if not naive) implementation of the Commons RDF API using in-memory POJO objects.

Note that although this module fully implements the commons-rdf API, it should not be considered a reference implementation. It is not thread-safe nor scalable, but may be useful for testing and simple usage (e.g. output from an independent RDF parser).

Projects including Apache Jena and OpenRDF Sesame aim to provide complete and scalable implementations of the Commons RDF API.

Testing

The abstract classes AbstractGraphTest and AbstractRDFTermFactoryTest can be realised as JUnit tests by implementations in order to verify that they pass the minimal requirements of this API.

In order for this to work, your project will need to depend on the tests classifier, for example (for Maven):

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>com.github.commons-rdf</groupId>
    <artifactId>commons-rdf-api</artifactId>
    <version>0.0.3-SNAPSHOT</version>
    <classifier>tests</classifier>
    <scope>test</scope>
</dependency>

The extensions of each Test class needs to provide a RDFTermFactory that can create the corresponding implementations of a Graph, IRI, etc.

For an example, see SimpleGraphTest.

Contributors

Sergio Fernández (Apache Marmotta)
Andy Seaborne (Apache Jena)
Peter Ansell (OpenRDF Sesame)
Stian Soiland-Reyes (Apache Taverna)

See CONTRIBUTING.md for details on how to contribute. In short - raise a Github pull request.

License

Apache License, Version 2.0

ianwdunlop/commons-rdf