prajna.ontology

Class OwlLoader

java.lang.Object

prajna.ontology.OwlLoader

Direct Known Subclasses:

SwrlReader

public class OwlLoader
extends java.lang.Object

Loader for loading RDF and OWL ontology files. This class loads the ontology definitions from RDF or OWL files, either locally or on the web, and creates all OwlClasses, properties, and OwlThings defined in the ontology. The OwlLoader is implemented as a Singleton class.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
OwlLoader()

Method Summary

Methods

Modifier and Type	Method and Description
java.util.Set<java.net.URL>	getLoadedUrls() Get the set of URLS that have been loaded
OwlOntology	getOntology(java.net.URL url) Get the Ontology definition for an ontology that has already been loaded.
boolean	isLoaded(java.net.URL url) Return whether the given URL has been loaded
OwlOntology	loadData(java.lang.String fileName) Load the ontology data from the specified file.
OwlOntology	loadData(java.net.URL url) Load the ontology data from the specified URL.
protected void	parseUnknownElement(org.w3c.dom.Element elem) Parse an element with an unknown tag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OwlLoader

public OwlLoader()

Method Detail

getLoadedUrls

public java.util.Set<java.net.URL> getLoadedUrls()

Get the set of URLS that have been loaded

Returns:

the set of URLS that have been loaded

getOntology

public OwlOntology getOntology(java.net.URL url)

Get the Ontology definition for an ontology that has already been loaded.

Parameters:

url - The URL reference for the ontology

Returns:

the ontology definition object

isLoaded

public boolean isLoaded(java.net.URL url)

Return whether the given URL has been loaded

Parameters:

url - the URL to check

Returns:

true if an ontology has been loaded with the given URL, false otherwise

loadData

public OwlOntology loadData(java.lang.String fileName)
                     throws java.io.IOException,
                            org.xml.sax.SAXException

Load the ontology data from the specified file. The argument may either be a local file path or a URL on the web.

Parameters:

fileName - the file name or URL path for the ontology

Returns:

the URL used to load the data

Throws:

java.io.IOException - If there is a problem reading the file

org.xml.sax.SAXException - if there is a problem parsing the file

loadData

public OwlOntology loadData(java.net.URL url)
                     throws java.io.IOException,
                            org.xml.sax.SAXException

Load the ontology data from the specified URL.

Parameters:

url - the URL path for the ontology

Returns:

the ontology loaded

Throws:

java.io.IOException - If there is a problem reading the file

org.xml.sax.SAXException - if there is a problem parsing the file

parseUnknownElement

protected void parseUnknownElement(org.w3c.dom.Element elem)

Parse an element with an unknown tag. This method allows the OwlLoader to be extended to incorporate extensions to OWL. The default implementation does nothing.

Parameters:

elem - the element to parse