fedora.server.validation
Class RelsExtValidator

java.lang.Object
  org.xml.sax.helpers.DefaultHandler
      fedora.server.validation.RelsExtValidator

All Implemented Interfaces:

org.xml.sax.ContentHandler, org.xml.sax.DTDHandler, org.xml.sax.EntityResolver, org.xml.sax.ErrorHandler

public class RelsExtValidator

extends org.xml.sax.helpers.DefaultHandler

Title: RelsExtValidator.java

Description: This class will validate relationship metadata that may exist in a digital object. The validator will SAX parse the content of the RELS-EXT datastream which must be an RDF stream that asserts object-to-object relationships for a digital object. The validator will enforce the following restrictions on the RDF stream: 1. The RDF must follow a prescribed RDF/XML authoring style where there is ONE subject encoded as an RDF with an RDF 'about' attribute containing a digital object URI. The sub-elements are the relationship properties of the subject. Each relationship refers to another digital object URI via an RDF 'resource' attribute. Relationship assertions can be from the default Fedora relationship ontology, or from other namespaces. For example: 2. There must be only ONE RDF in the RELS-EXT datastream. 3. There must be NO nesting of assertions. In terms of XML depth, the RDF root element is considered depth of 0. Then, the RDF must be at depth of 1, and the relationship properties must exist at depth of 2. That's it. 4. The RDF 'about' attribute of the RDF must be the URI of the digital object in which the RELS-EXT datastream resides. This means that all relationships are FROM "this" object to other objects. 5. The RDF 'resource' attribute of a relationship assertion must be the URI of another Fedora digital object. This is because the RELS-EXT datastream is for object-to-object relationships. 6. The RDF 'resource' attribute of a relationship assertion must NOT be the URI of the digital object that is the subject of the relationships. In other words, NO SELF-REFERENTIAL relationships. 7. There must NOT be any assertion of properties from the DC namespace or from the Fedora object properties namespaces (model and view). This is because these assertions exist elsewhere in a Fedora digital object and we do not want duplication. The RELS-EXT datasream is reserved for relationship metadata.

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License and Copyright: The contents of this file are subject to the Mozilla Public License Version 1.1 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.mozilla.org/MPL/.

Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License.

The entire file consists of original code. Copyright © 2002-2005 by The Rector and Visitors of the University of Virginia and Cornell University. All rights reserved.

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Version:

$Id: RelsExtValidator.java,v 1.3 2005/01/11 20:06:09 cwilper Exp $

Author:

payette@cs.cornell.edu

Constructor Summary

RelsExtValidator(java.lang.String characterEncoding, boolean validate)

Method Summary

void	deserialize(java.io.InputStream relsDS, java.lang.String doURI)
void	endElement(java.lang.String nsURI, java.lang.String localName, java.lang.String qName)
RelsExtValidator	getInstance()
void	startElement(java.lang.String nsURI, java.lang.String localName, java.lang.String qName, org.xml.sax.Attributes a)

Methods inherited from class org.xml.sax.helpers.DefaultHandler

characters, endDocument, endPrefixMapping, error, fatalError, ignorableWhitespace, notationDecl, processingInstruction, resolveEntity, setDocumentLocator, skippedEntity, startDocument, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

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

Constructor Detail

RelsExtValidator

public RelsExtValidator(java.lang.String characterEncoding,
                        boolean validate)
                 throws javax.xml.parsers.FactoryConfigurationError,
                        javax.xml.parsers.ParserConfigurationException,
                        org.xml.sax.SAXException,
                        java.io.UnsupportedEncodingException

Method Detail

getInstance

public RelsExtValidator getInstance()
                             throws RepositoryConfigurationException

Throws:

RepositoryConfigurationException

deserialize

public void deserialize(java.io.InputStream relsDS,
                        java.lang.String doURI)
                 throws ObjectIntegrityException,
                        StreamIOException,
                        org.xml.sax.SAXException

Throws:

ObjectIntegrityException

StreamIOException

org.xml.sax.SAXException

startElement

public void startElement(java.lang.String nsURI,
                         java.lang.String localName,
                         java.lang.String qName,
                         org.xml.sax.Attributes a)
                  throws org.xml.sax.SAXException

Throws:

org.xml.sax.SAXException

endElement

public void endElement(java.lang.String nsURI,
                       java.lang.String localName,
                       java.lang.String qName)