org.dspace.content.crosswalk
Class SimpleDCDisseminationCrosswalk

java.lang.Object
  extended by org.dspace.core.SelfNamedPlugin
      extended by org.dspace.content.crosswalk.SimpleDCDisseminationCrosswalk
All Implemented Interfaces:
DisseminationCrosswalk

public class SimpleDCDisseminationCrosswalk
extends SelfNamedPlugin
implements DisseminationCrosswalk

Disseminator for Simple Dublin Core metadata in XML format. Logic stolen from OAIDCCrosswalk. This is mainly intended as a proof-of-concept, to use crosswalk plugins in the OAI-PMH server.

Version:
$Revision: 3761 $
Author:
Larry Stone

Field Summary
 
Fields inherited from interface org.dspace.content.crosswalk.DisseminationCrosswalk
XSI_NS
 
Constructor Summary
SimpleDCDisseminationCrosswalk()
           
 
Method Summary
 boolean canDisseminate(DSpaceObject dso)
          Predicate: Can this disseminator crosswalk the given object.
 org.jdom.Element disseminateElement(DSpaceObject dso)
          Execute crosswalk, returning one XML root element as a JDOM Element object.
 List disseminateList(DSpaceObject dso)
          Returns object's metadata as XML elements.
 List disseminateListInternal(DSpaceObject dso, boolean addSchema)
           
 org.jdom.Namespace[] getNamespaces()
          Get XML namespaces of the elements this crosswalk may return.
static String[] getPluginNames()
           
 String getSchemaLocation()
          Get the XML Schema location(s) of the target metadata format.
 boolean preferList()
          Predicate: Does this disseminator prefer to return a list of Elements, rather than a single root Element?
 
Methods inherited from class org.dspace.core.SelfNamedPlugin
getPluginInstanceName, setPluginInstanceName
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SimpleDCDisseminationCrosswalk

public SimpleDCDisseminationCrosswalk()
Method Detail

getPluginNames

public static String[] getPluginNames()

disseminateElement

public org.jdom.Element disseminateElement(DSpaceObject dso)
                                    throws CrosswalkException,
                                           IOException,
                                           SQLException,
                                           AuthorizeException
Description copied from interface: DisseminationCrosswalk
Execute crosswalk, returning one XML root element as a JDOM Element object. This is typically the root element of a document.

Specified by:
disseminateElement in interface DisseminationCrosswalk
Parameters:
dso - the DSpace Object whose metadata to export.
Returns:
root Element of the target metadata, never null
Throws:
CrosswalkInternalException - (CrosswalkException) failure of the crosswalk itself.
CrosswalkObjectNotSupported - (CrosswalkException) Cannot crosswalk this kind of DSpace object.
IOException - I/O failure in services this calls
SQLException - Database failure in services this calls
AuthorizeException - current user not authorized for this operation.
CrosswalkException

disseminateList

public List disseminateList(DSpaceObject dso)
                     throws CrosswalkException,
                            IOException,
                            SQLException,
                            AuthorizeException
Returns object's metadata as XML elements. Simple-minded copying of elements: convert contributor.author to "creator" but otherwise just grab element name without qualifier.

Specified by:
disseminateList in interface DisseminationCrosswalk
Parameters:
dso - the DSpace Object whose metadata to export.
Returns:
results of crosswalk as list of XML elements.
Throws:
CrosswalkInternalException - (CrosswalkException) failure of the crosswalk itself.
CrosswalkObjectNotSupported - (CrosswalkException) Cannot crosswalk this kind of DSpace object.
IOException - I/O failure in services this calls
SQLException - Database failure in services this calls
AuthorizeException - current user not authorized for this operation.
CrosswalkException

disseminateListInternal

public List disseminateListInternal(DSpaceObject dso,
                                    boolean addSchema)
                             throws CrosswalkException,
                                    IOException,
                                    SQLException,
                                    AuthorizeException
Throws:
CrosswalkException
IOException
SQLException
AuthorizeException

getNamespaces

public org.jdom.Namespace[] getNamespaces()
Description copied from interface: DisseminationCrosswalk
Get XML namespaces of the elements this crosswalk may return. Returns the XML namespaces (as JDOM objects) of the root element.

Specified by:
getNamespaces in interface DisseminationCrosswalk
Returns:
array of namespaces, which may be empty.

getSchemaLocation

public String getSchemaLocation()
Description copied from interface: DisseminationCrosswalk
Get the XML Schema location(s) of the target metadata format. Returns the string value of the xsi:schemaLocation attribute that should be applied to the generated XML.

It may return the empty string if no schema is known, but crosswalk authors are strongly encouraged to implement this call so their output XML can be validated correctly.

Specified by:
getSchemaLocation in interface DisseminationCrosswalk
Returns:
SchemaLocation string, including URI namespace, followed by whitespace and URI of XML schema document, or empty string if unknown.

canDisseminate

public boolean canDisseminate(DSpaceObject dso)
Description copied from interface: DisseminationCrosswalk
Predicate: Can this disseminator crosswalk the given object. Needed by OAI-PMH server implementation.

Specified by:
canDisseminate in interface DisseminationCrosswalk
Parameters:
dso - dspace object, e.g. an Item.
Returns:
true when disseminator is capable of producing metadata.

preferList

public boolean preferList()
Description copied from interface: DisseminationCrosswalk
Predicate: Does this disseminator prefer to return a list of Elements, rather than a single root Element?

Some metadata formats have an XML schema without a root element, for example, the Dublin Core and Qualified Dublin Core formats. This would be true for a crosswalk into QDC, since it would "prefer" to return a list, since any root element it has to produce would have to be part of a nonstandard schema. In most cases your implementation will want to return false

Specified by:
preferList in interface DisseminationCrosswalk
Returns:
true when disseminator prefers you call disseminateList().


Copyright © 2010 DuraSpace. All Rights Reserved.