Package com.hp.hpl.jena.rdf.arp

Reading RDF/XML.

See:
Description

Interface Summary

ALiteral	A string literal property value from an RDF/XML file.
AResource
ARPErrorNumbers	Error numbers used by ARP.
ARPHandler	Convenience generalization of all ARP handler interfaces.
ExtendedHandler	Extended callbacks from a reader to an RDF application.
NamespaceHandler	This has methods copied form SAX for notifying the application of namespaces.
RDFParserConstants
StatementHandler	The callback from a reader to an RDF application.

Class Summary

ARP	Another RDF Parser.
ARPSaxErrorHandler	This class is not part of the API.
CharacterModel	Some support for the Character Model Recommendation from the W3C (currently in second last call working draft).
JenaReader	Interface between Jena and ARP.
NTriple	A command line interface into ARP.
StanfordImpl	An implementation of Sergey Melnik's Stanford API, used by SiRPAC.
URI	A class to represent a Uniform Resource Identifier (URI).

Exception Summary

MalformedURIException	MalformedURIExceptions are thrown in the process of building a URI or setting fields on a URI when an operation would result in an invalid URI specification.
ParseException	An exception during the RDF processing of ARP.

Package com.hp.hpl.jena.rdf.arp Description

Reading RDF/XML.

The interaction between ARP and Xerces includes a significant memory leak probably caused by Xerces interning some strings, on behalf of ARP. This feature cannot be turned off. This is not a new bug, so ARP users will not experience a degradation in performance. However, for users who have limited memory, or who are processing large files, or files from many diverse sources, or for long-lived applications such as web servers, it is important to be aware of this leak. I believe that the strings being interned correspond to the XML element tags and attribute names in the XML document. These form an open set in RDF/XML, unlike most XML applications.

No proper work around is provided at this time; it is hoped that later enhancements will provide a non-Xerces solution.

The best current advice is as follows:

limited memory environments

buy more memory

convert RDF/XML to N3 or N-triple before sending to the limited memory application.

long-lived applications

web servers

Kill and restart you application regularly e.g. daily. Monitor memory usage to check whether the application should be restarted more frequently.

very large documents

Ensure these are processed in environments with adequate memory, restart application after each job.

The size of the leak is presumably highly dependent on the actual RDF/XML documents read. As an example the OWL Guide wine ontology, (using the version from the OWL Test Cases) contains about 2000 triples and leaks about 180K.