org.dspace.content.crosswalk

Class SimpleDCDisseminationCrosswalk

java.lang.Object

org.dspace.core.SelfNamedPlugin

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:

$Revision$

Author:

Larry Stone

Field Summary

Fields

Modifier and Type	Field and Description
protected ItemService	itemService

Fields inherited from interface org.dspace.content.crosswalk.DisseminationCrosswalk

XSI_NS

Constructor Summary

Constructors

Constructor and Description
SimpleDCDisseminationCrosswalk()

Method Summary

Modifier and Type	Method and Description
boolean	canDisseminate(DSpaceObject dso) Predicate: Can this disseminator crosswalk the given object.
org.jdom.Element	disseminateElement(Context context, DSpaceObject dso) Execute crosswalk, returning one XML root element as a JDOM Element object.
List<org.jdom.Element>	disseminateList(Context context, DSpaceObject dso) Returns object's metadata as XML elements.
List<org.jdom.Element>	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

Field Detail

itemService

protected final ItemService itemService

Constructor Detail

SimpleDCDisseminationCrosswalk

public SimpleDCDisseminationCrosswalk()

Method Detail

getPluginNames

public static String[] getPluginNames()

disseminateElement

public org.jdom.Element disseminateElement(Context context,
                                           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:

context - context

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<org.jdom.Element> disseminateList(Context context,
                                              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:

context - context

dso - the DSpace Object whose metadata to export.

Returns:

results of crosswalk as list of XML elements.

Throws:

CrosswalkException - if crosswalk error

IOException - if IO error

SQLException - if database error

AuthorizeException - if authorization error

disseminateListInternal

public List<org.jdom.Element> 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().