Apache Jena is an open source Semantic Web framework for

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...

. It provides an

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

to extract data from and write to RDF graphs. The graphs are represented as an abstract "model". A model can be sourced with data from files, databases, URLs or a combination of these. A model can also be queried through

SPARQL SPARQL (pronounced " sparkle" , a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language—that is, a semantic query language for databases—able to retrieve and manipulate data stored in Resource Description ...

1.1. Jena is similar to

RDF4J Eclipse RDF4J (formerly OpenRDF Sesame) is an open-source framework for storing, querying, and analysing RDF data. It was created by the Dutch software company Aduna as part of "On-To-Knowledge", a semantic web project that ran from 1999 to 2002 ...

(formerly OpenRDF Sesame); though, unlike RDF4J, Jena provides support for OWL (

Web Ontology Language The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for vario ...

). The framework has various internal reasoners and the Pellet reasoner (an open source Java OWL-DL reasoner) can be set up to work in Jena. Jena supports serialisation of RDF graphs to: *a relational database *

RDF/XML RDF/XML is a syntax,RDF/XML Syntax Specification
Turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

* TriG *

Notation 3 Notation3, or N3 as it is more commonly known, is a shorthand non-XML serialization of Resource Description Framework models, designed with human-readability in mind: N3 is much more compact and readable than XML RDF notation. The format is being ...

JSON-LD JSON-LD (JavaScript Object Notation for Linked Data) is a method of encoding linked data using JSON. One goal for JSON-LD was to require as little effort as possible from developers to transform their existing JSON to JSON-LD. JSON-LD allows data ...

Versions

After Apache integration

Jena was integrated as a project under the umbrella of The Apache Software Foundation in April 2012, after having been in the

Apache Incubator Apache Incubator is the gateway for open-source projects intended to become fully fledged Apache Software Foundation projects. The Incubator project was created in October 2002 to provide an entry path to the Apache Software Foundation for projec ...

since November 2010.

Before Apache integration

Jena was created by HP Labs and was on

SourceForge SourceForge is a web service that offers software consumers a centralized online location to control and manage open-source software projects and research business software. It provides source code repository hosting, bug tracking, mirroring ...

since 2001, and was donated to The Apache Software Foundation in November 2010.

Fuseki

Fuseki ''Fuseki'' (Japanese: ; ) is the whole board opening in the game of Go. Characteristics Less systematic Since each move is typically isolated and unforced (i.e. not a sente move), patterns for play on the whole board have seen much less sy ...

is an HTTP interface to RDF data. It supports

for querying and updating. The project is a sub-project of Jena and is developed as

servlet A Jakarta Servlet (formerly Java Servlet) is a Java software component that extends the capabilities of a server. Although servlets can respond to many types of requests, they most commonly implement web containers for hosting web application ...

. Fuseki can also be run stand-alone server as it ships preconfigured with the

Jetty A jetty is a structure that projects from land out into water. A jetty may serve as a breakwater, as a walkway, or both; or, in pairs, as a means of constricting a channel. The term derives from the French word ', "thrown", signifying some ...

web server.

ARQ

ARQ is a query engine within Jena that supports

References

External links

Jena Jena () is a German city and the second largest city in Thuringia. Together with the nearby cities of Erfurt and Weimar, it forms the central metropolitan area of Thuringia with approximately 500,000 inhabitants, while the city itself has a po ...

Resource Description Framework Semantic Web Triplestores {{free-software-stub