Jena

Jena - Reasoners and rule engines: Jena inference support. This section of the documentation describes the current support for inference available within Jena.

It includes an outline of the general inference API, together with details of the specific rule engines and configurations for RDFS and OWL inference supplied with Jena. Not all of the fine details of the API are covered here: refer to the Jena Javadoc to get the full details of the capabilities of the API. Note that this is a preliminary version of this document, some errors or inconsistencies are possible, feedback to the mailing lists is welcomed.

Index Overview of inference support The Jena inference subsystem is designed to allow a range of inference engines or reasoners to be plugged into Jena. We will try to use the term inference to refer to the abstract process of deriving additional information and the term reasoner to refer to a specific code object that performs this task. The overall structure of the inference machinery is illustrated below. Available reasoners [index] Validation or. Jena Ontology API. This section is a general introduction to the Jena2 ontology API, including some of the common tasks you may need to perform.

We won't go into all of the many details of the API here: you should expect to refer to the Javadoc to get full details of the capabilities of the API. Prerequisites We'll assume that you have a basic familiarity with RDF and with Jena. If not, there are other Jena help documents you can read for background on these topics, and a collection of tutorials. Jena is a programming toolkit, using the Java programming language. We also won't be explaining the OWL or RDFS ontology languages in much detail in this document. Note: Although OWL version 1.1 is now a W3C recommendation, Jena's support for OWL 1.1 features is limited. Overview The section of the manual is broken into a number of sections. Further assistance Hopefully, this document will be sufficient to help most readers to get started using the Jena ontology API. General concepts Ontologies and reasoning. Complete beginner's guide to starting a Jena project in Eclipse. A complete beginner's guide to starting a Jena project in Eclipse I fairly often get email of the following form: Dear Mr/Dr/Professor Dickinson I am Jena newbie.

I can't attach the jena to eclipse. could you please give me help to resolve this problem. I'm not a prof, by the way, but it's flattering to be promoted! So this article is for all those who are new to Jena and Eclipse. A Java programming tutorial Instructions for installing Eclipse A comprehensive Jena tutorial Instead, my goals for this article are to show you how get the most basic possible Jena program set up in Eclipse. Preamble. Introduction au RDF et à l'API RDF de Jena. Le RDF est un standard (techniquement une recommandation du W3C) pour la description de ressources.

Qu'est-ce qu'une ressource ? C'est une question plutôt profonde et la définition précise est toujours l'objet de débats. Pour nos fins, on peut imaginer que c'est tout ce que l'on peut identifier. Vous êtes une ressource, comme l'est votre page d'accueil, ce tutoriel ou la baleine blanche de Moby Dick. Nos exemples dans ce tutoriel seront des personnes. La ressource, John Smith, est représentée comme une ellipse et est identifiée par un identifiant de ressource uniforme (URI (1) ), dans ce cas Si vous essayez d'accéder à cette ressource en utilisant votre navigateur, vous n'y arriverez probablement pas ; résistant à la tentation du poisson d'avril, vous seriez plutôt surpris qu'un navigateur puisse vous amener John Smith sur votre bureau.

Les ressources possèdent des propriétés. Chaque propriété a une valeur. Le code pour créer ce graphe, ou modèle, est simple : SPARQL by Example. Jena - SDB - persistent triple stores using relational databases. SDB - persistent triple stores using relational databases SDB uses an SQL database for the storage and query of RDF data.

Many databases are supported, both Open Source and proprietary. An SDB store can be accessed and managed with the provided command line scripts and via the Jena API. Use of SDB for new applications is not recommended. This component is "maintenance only". TDB is faster, more scalable and better supported than SDB. Status As of June 2013 the Jena developers agreed to treat SDB as being only maintanined where possible. The developers intend to continue releasing SDB alongside other Jena components but it is not actively developed. SDB may be revived as a fully supported component if members of the community come forward to develop it.

Documentation Downloads. Tutorial V: SPARQL Extensions using: Aggregates, Date Arithmetic, Sub-queries, Path Expressions, Inference Rules and Geography.