org.fcrepo.server.validation
Class RelsValidator

java.lang.Object
  org.xml.sax.helpers.DefaultHandler
      org.fcrepo.server.validation.RelsValidator

All Implemented Interfaces:

Constants, ContentHandler, DTDHandler, EntityResolver, ErrorHandler

public class RelsValidator
extends DefaultHandler
implements Constants

Validates the RDF/XML content of the RELS-EXT and RELS-INT datastreams.

The following restrictions are enforced:

• The RDF must follow a prescribed RDF/XML authoring style where there is ONE (RELS-EXT) or more (RELS-INT) subjects encoded as RDF <Description> elements with RDF about attribute containing either a digital object URI (RELS-EXT) or a datastream URI (RELS-INT). The sub-elements are the relationship properties of the subject. Each relationship may refer to any resource (identified by URI) via an RDF 'resource' attribute, or a literal. Relationship assertions can be from the default Fedora relationship ontology, or from other namespaces.
  • RELS-EXT example:

    <rdf:Description about="info:fedora/demo:5">
       <fedora:isMemberOfCollection resource="info:fedora/demo:100"/>
       <nsdl:isAugmentedBy resource="info:fedora/demo:333"/>
       <example:source resource="http://example.org/bsmith/article1.html"/>
       <example:primaryAuthor>Bob Smith</example:primaryAuthor>
     </rdf:Description>
     

  • RELS-INT example:

    <rdf:Description about="info:fedora/demo:5/DS1">
       <nsdl:isAugmentedBy resource="info:fedora/demo:333"/>
       <example:source resource="http://example.org/bsmith/article1.html"/>
       <example:primaryAuthor>Bob Smith</example:primaryAuthor>
     </rdf:Description>
     

• For RELS-EXT, there must be only ONE <rdf:Description> element.
• There must be NO nesting of assertions. In terms of XML depth, the RDF root element is considered depth of 0. Then, the <rdf:Description> element must be at depth of 1, and the relationship properties must exist at depth of 2. That's it.
• For RELS-EXT, The RDF about attribute of the RDF <Description> 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.
• For RELS-INT, the RDF about attribute(s) of the RDF <Description> element(s) must be valid URIs of datastreams for the digital object in which the RELS-EXT datastream resides. The datastreams do not actually have to exist, but these URIs must be syntactically valid. This means that all relationships are FROM datastreams in "this" object to other objects.
• If the target of the statement is a resource (identified by a URI), the RDF resource attribute must specify a syntactically valid, absolute URI.
• For RELS-EXT, there must NOT be any assertion of properties from the DC namespace.
• There must NOT be any assertions of properties from the Fedora object properties namespaces (model and view), with the following exceptions for RELS-EXT only:

   fedora-model:hasService
   fedora-model:hasModel
   fedora-model:isDeploymentOf
   fedora-model:isContractorOf
          These assertions are allowed in the RELS-EXT datastream, but all
          others from the fedora-model and fedora-view
          namespaces are inferred from values expressed elsewhere in the
          digital object, and we do not want duplication.
   

Author:

Sandy Payette, Eddie Shin, Chris Wilper, Stephen Bayliss

Nested Class Summary

Nested classes/interfaces inherited from interface org.fcrepo.common.Constants

Constants.FedoraHome

Field Summary

Fields inherited from interface org.fcrepo.common.Constants

ACCESS, ACTION, API, ATOM_APIM1_0, ATOM_ZIP1_1, ATOM1_1, AUDIT, AUDIT1_0, BATCH_MODIFY, BATCH_MODIFY1_1, BE_SECURITY, BE_SECURITY1_0, BINDING_SPEC, DATASTREAM, DC, DISSEMINATOR, DS_COMPOSITE_MODEL, DS_COMPOSITE_MODEL1_0, DS_INPUT_SPEC1_0, DS_INPUT_SPEC1_1, ENVIRONMENT, FCFG, FEDORA, FEDORA_APP_CONTEXT_NAME, FEDORA_DEFAULT_APP_CONTEXT, FEDORA_HOME, FOXML, FOXML1_0, FOXML1_0_LEGACY, FOXML1_1, HTTP_REQUEST, MANAGEMENT, METHOD_MAP, METS, METS_EXT, METS_EXT1_0, METS_EXT1_0_LEGACY, METS_EXT1_1, MODEL, MULGARA, OAI_DC, OAI_DC2_0, OAI_FRIENDS, OAI_FRIENDS2_0, OAI_IDENTIFIER, OAI_IDENTIFIER2_0, OAI_PMH, OAI_PMH2_0, OAI_PROV, OAI_PROV2_0, OBJ_DATASTREAMS1_0, OBJ_HISTORY1_0, OBJ_ITEMS1_0, OBJ_METHODS1_0, OBJ_PROFILE1_0, OBJ_VALIDATION1_0, OBJECT, OLD_XLINK, PID_LIST1_0, RDF, RDF_XSD, RECOVERY, RELS_EXT1_0, RELS_INT1_0, REPO_DESC1_0, RESOURCE, SDEF, SDEF_METHOD_MAP1_0, SDEP, SDEP_METHOD_MAP1_0, SDEP_METHOD_MAP1_1, SERVICE_PROFILE, SOAP, SOAP_ENC, SUBJECT, TYPES, VIEW, WSDL, WSDL_HTTP, WSDL_MIME, XACML_POLICY, XACML_POLICY1_0, XLINK, XML_XSD, XMLNS, XSI

Constructor Summary

RelsValidator()

Method Summary

void	characters(char[] ch, int start, int length)
void	endElement(String nsURI, String localName, String qName)
void	startElement(String nsURI, String localName, String qName, Attributes a)
void	validate(PID pid, String dsId, InputStream content)

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

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

RelsValidator

public RelsValidator()

Method Detail

validate

public void validate(PID pid,
                     String dsId,
                     InputStream content)
              throws ValidationException

Throws:

ValidationException

startElement

public void startElement(String nsURI,
                         String localName,
                         String qName,
                         Attributes a)
                  throws SAXException

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class DefaultHandler

Throws:

SAXException

characters

public void characters(char[] ch,
                       int start,
                       int length)

Specified by:

characters in interface ContentHandler

Overrides:

characters in class DefaultHandler

endElement

public void endElement(String nsURI,
                       String localName,
                       String qName)
                throws SAXException

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class DefaultHandler

Throws:

SAXException