Copyright © 2005 Andreas Harth. All Rights Reserved.
Version: 0.1, 30 June 2005.
Download: http://sw.deri.org/2004/06/yars/dist/yars-current.war (Server) http://sw.deri.org/2004/06/yars/dist/yars-current.jar (Client)
Source control: Available from Subversion at http://sw.deri.org/svn/sw/2004/06/yars/.
Contact person: Andreas Harth, andreas.harth@deri.org
YARS is a data store for RDF in Java. YARS uses [Notation 3] as a way to encode facts and queries. The current version supports tree-shaped datalog queries with one shared variable. The interface for interacting with YARS is HTTP (GET, PUT, and DELETE) and built upon the REST (Representational State Transfer) principle. YARS supports keywords searches, and will have content-negotiatible result formats (RDF/N3, XML, and HTML).
Much more information can be found on the YARS wiki.
Please note that YARS is intented for storage and retrieval of RDF, which offers a somewhat higher abstraction layer than the APIs of RDF toolkits such as Jena or Redland.
The current version 0.1 of YARS is a pre-release with limited functionality. The main goal is to provide early access to the APIs and the system and to illustrate the architecture. The core functionality (scalable storage and querying) works, and the access interface via HTTP is stable.
A command line client for Linux has functionality to add data to a YARS instance. Queries can be posed using any web browser. There is also a demonstration client in alpha-quality available to add, delete, and query data from within a GUI.
Nature: A Web application for use in Servlet containers.
Interfaces (API, Web Services): a HTTP REST interface.
Platform: JDK 1.4.2.
Supported standards:
Required Libraries (OMWG, SDK Cluster, WSMO-related):
Required Libraries (others):
Copyright (c) 2004, 2005, Andreas Harth
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Licensing of third party libraries and components required for ORDI:
YARS is distributed as a web application (war) archive for
deployment in a servlet container such as Apache Tomcat or Jetty. To deploy YARS, one
needs to copy the yars.war file to the web
applications directory of the servlet container and restart the
servlet container.
An ant build.xml is included in the source
distribution and has targets to clean up, build and generate both
jar and war files, and deploy the .war
In the following section we provide a simple walkthrough
scenario to illustrate how YARS can be used. $WEBAPP
is the web application directory of the servlet container.
yars-current.war to
$WEBAPP/yars.war and restart your servlet
containeryars-current.jar or with java -jar
yars-current.jar
@prefix : <http://sw.deri.org/2004/06/yars#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix ql: <http://www.w3.org/2004/12/ql#> .
<> ql:where {
?x foaf:name ?n .
} .
?x and ?nThe major driving forces for the future development of YARS:
Below follows a non-exhaustive list of tasks, which fit into the short-term development plans:
The next release of YARS is planned for the end of December 2005.
[Notation3] Tim Berners-Lee: An RDF language for the Semantic Web http://www.w3.org/DesignIssues/Notation3.html
[YARS] Andreas Harth, Stefan Decker: Optimized Index Structures for Querying RDF from the Web http://sw.deri.org/2005/02/dexa/yars.pdf
$Date: 2005/06/30 12:40:12 $