/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.content.crosswalk;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import org.dspace.authorize.AuthorizeException;
import org.dspace.content.DSpaceObject;
import org.dspace.content.packager.PackageDisseminator;
import org.dspace.content.packager.PackageException;
import org.dspace.content.packager.PackageIngester;
import org.dspace.content.packager.PackageParameters;
import org.dspace.content.packager.RoleDisseminator;
import org.dspace.core.ConfigurationManager;
import org.dspace.core.Constants;
import org.dspace.core.Context;
import org.dspace.core.PluginManager;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.Namespace;
import org.jdom.input.SAXBuilder;
import org.jdom.output.XMLOutputter;
/**
* Role Crosswalk
* <p>
* Translate between DSpace Group & EPeople definitions and a DSpace-specific
* XML export format (generated by the RoleDisseminator). This is primarily
* used for AIPs, but may be used by other Packagers as necessary.
* <p>
* This crosswalk allows you to export DSpace Groups & EPeople to this XML
* structured format. It also allows you to import an XML file of this format
* in order to restore DSpace Groups and EPeople defined within it.
* <p>
* This is just wrappers; the real work is done in RoleDisseminator and
* RoleIngester.
*
* @author mwood
* @author Tim Donohue
* @see org.dspace.content.packager.RoleDisseminator
* @see org.dspace.content.packager.RoleIngester
* @see AbstractPackagerWrappingCrosswalk
* @see IngestionCrosswalk
* @see DisseminationCrosswalk
*/
public class RoleCrosswalk
extends AbstractPackagerWrappingCrosswalk
implements IngestionCrosswalk, DisseminationCrosswalk
{
// Plugin Name of DSPACE-ROLES packager to use for ingest/dissemination
// (Whatever plugin is defined with this name in 'dspace.cfg' will be used by this Crosswalk)
private static final String ROLE_PACKAGER_PLUGIN = "DSPACE-ROLES";
// ---- Dissemination Methods -----------
/**
* Get XML namespaces of the elements this crosswalk may return.
* Returns the XML namespaces (as JDOM objects) of the root element.
*
* @return array of namespaces, which may be empty.
*/
@Override
public Namespace[] getNamespaces()
{
Namespace result[] = new Namespace[1];
result[0] = RoleDisseminator.DSROLES_NS;
return result;
}
/**
* Get the XML Schema location(s) of the target metadata format.
* Returns the string value of the <code>xsi:schemaLocation</code>
* attribute that should be applied to the generated XML.
* <p>
* 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.
* @return SchemaLocation string, including URI namespace, followed by
* whitespace and URI of XML schema document, or empty string if unknown.
*/
@Override
public String getSchemaLocation()
{
return "";
}
/**
* Predicate: Can this disseminator crosswalk the given object.
*
* @param dso dspace object, e.g. an <code>Item</code>.
* @return true when disseminator is capable of producing metadata.
*/
@Override
public boolean canDisseminate(DSpaceObject dso)
{
//We can only disseminate SITE, COMMUNITY or COLLECTION objects,
//as Groups are only associated with those objects.
return (dso.getType() == Constants.SITE ||
dso.getType() == Constants.COMMUNITY ||
dso.getType() == Constants.COLLECTION);
}
/**
* Predicate: Does this disseminator prefer to return a list of Elements,
* rather than a single root Element?
*
* @return true when disseminator prefers you call disseminateList().
*/
@Override
public boolean preferList()
{
//We prefer disseminators call 'disseminateElement()' instead of 'disseminateList()'
return false;
}
/**
* Execute crosswalk, returning List of XML elements.
* Returns a <code>List</code> of JDOM <code>Element</code> objects representing
* the XML produced by the crosswalk. This is typically called when
* a list of fields is desired, e.g. for embedding in a METS document
* <code>xmlData</code> field.
* <p>
* When there are no results, an
* empty list is returned, but never <code>null</code>.
*
* @param dso the DSpace Object whose metadata to export.
* @return results of crosswalk as list of XML elements.
*
* @throws CrosswalkInternalException (<code>CrosswalkException</code>) failure of the crosswalk itself.
* @throws CrosswalkObjectNotSupported (<code>CrosswalkException</code>) Cannot crosswalk this kind of DSpace object.
* @throws IOException I/O failure in services this calls
* @throws SQLException Database failure in services this calls
* @throws AuthorizeException current user not authorized for this operation.
*/
@Override
public List<Element> disseminateList(DSpaceObject dso)
throws CrosswalkException, IOException, SQLException,
AuthorizeException
{
Element dim = disseminateElement(dso);
return dim.getChildren();
}
/**
* Execute crosswalk, returning one XML root element as
* a JDOM <code>Element</code> object.
* This is typically the root element of a document.
* <p>
*
* @param dso the DSpace Object whose metadata to export.
* @return root Element of the target metadata, never <code>null</code>
*
* @throws CrosswalkInternalException (<code>CrosswalkException</code>) failure of the crosswalk itself.
* @throws CrosswalkObjectNotSupported (<code>CrosswalkException</code>) Cannot crosswalk this kind of DSpace object.
* @throws IOException I/O failure in services this calls
* @throws SQLException Database failure in services this calls
* @throws AuthorizeException current user not authorized for this operation.
*/
@Override
public Element disseminateElement(DSpaceObject dso)
throws CrosswalkException, IOException, SQLException,
AuthorizeException
{
try
{
PackageDisseminator dip = (PackageDisseminator)
PluginManager.getNamedPlugin(PackageDisseminator.class, ROLE_PACKAGER_PLUGIN);
if (dip == null)
{
throw new CrosswalkInternalException("Cannot find a PackageDisseminator plugin named " + ROLE_PACKAGER_PLUGIN);
}
// Create a temporary file to disseminate into
String tempDirectory = ConfigurationManager.getProperty("upload.temp.dir");
File tempFile = File.createTempFile("RoleCrosswalkDisseminate" + dso.hashCode(), null, new File(tempDirectory));
tempFile.deleteOnExit();
// Initialize our packaging parameters
PackageParameters pparams;
if(this.getPackagingParameters()!=null)
{
pparams = this.getPackagingParameters();
}
else
{
pparams = new PackageParameters();
}
//actually disseminate to our temp file.
Context context = new Context();
dip.disseminate(context, dso, pparams, tempFile);
context.complete();
// if we ended up with a Zero-length output file,
// this means dissemination was successful but had no results
if(tempFile.exists() && tempFile.length()==0)
{
return null;
}
try
{
//Try to parse our XML results (which were disseminated by the Packager)
SAXBuilder builder = new SAXBuilder();
Document xmlDocument = builder.build(tempFile);
//If XML parsed successfully, return root element of doc
if(xmlDocument!=null && xmlDocument.hasRootElement())
{
return xmlDocument.getRootElement();
}
else
{
return null;
}
}
catch (JDOMException je)
{
throw new MetadataValidationException("Error parsing Roles XML (see wrapped error message for more details) ",je);
}
}
catch (PackageException pe)
{
throw new CrosswalkInternalException("Failed to export Roles via packager (see wrapped error message for more details) ",pe);
}
}
// ---- Ingestion Methods -----------
/**
* Ingest a List of XML elements
*
* @param context
* @param dso
* @param metadata
* @throws CrosswalkException
* @throws IOException
* @throws SQLException
* @throws AuthorizeException
*/
@Override
public void ingest(Context context, DSpaceObject dso, List<Element> metadata)
throws CrosswalkException, IOException, SQLException, AuthorizeException
{
if(!metadata.isEmpty())
{
ingest(context, dso, ((Element) metadata.get(0)).getParentElement());
}
}
/**
* Ingest a whole XML document, starting at specified root.
* <P>
* This essentially just wraps a call to the configured Role PackageIngester.
*
* @param context
* @param dso
* @param root
* @throws CrosswalkException
* @throws IOException
* @throws SQLException
* @throws AuthorizeException
*/
@Override
public void ingest(Context context, DSpaceObject dso, Element root)
throws CrosswalkException, IOException, SQLException, AuthorizeException
{
if (dso.getType() != Constants.SITE &&
dso.getType() != Constants.COMMUNITY &&
dso.getType() != Constants.COLLECTION)
{
throw new CrosswalkObjectNotSupported("Role crosswalk only valid for Site, Community or Collection");
}
//locate our "DSPACE-ROLES" PackageIngester plugin
PackageIngester sip = (PackageIngester)
PluginManager.getNamedPlugin(PackageIngester.class, ROLE_PACKAGER_PLUGIN);
if (sip == null)
{
throw new CrosswalkInternalException("Cannot find a PackageIngester plugin named " + ROLE_PACKAGER_PLUGIN);
}
// Initialize our packaging parameters
PackageParameters pparams;
if(this.getPackagingParameters()!=null)
{
pparams = this.getPackagingParameters();
}
else
{
pparams = new PackageParameters();
}
// Initialize our license info
String license = null;
if(this.getIngestionLicense()!=null)
{
license = this.getIngestionLicense();
}
// Create a temporary file to ingest from
String tempDirectory = ConfigurationManager.getProperty("upload.temp.dir");
File tempFile = File.createTempFile("RoleCrosswalkIngest" + dso.hashCode(), null, new File(tempDirectory));
tempFile.deleteOnExit();
FileOutputStream fileOutStream = null;
try
{
fileOutStream = new FileOutputStream(tempFile);
XMLOutputter writer = new XMLOutputter();
writer.output(root, fileOutStream);
}
finally
{
if (fileOutStream != null)
{
fileOutStream.close();
}
}
//Actually call the ingester
try
{
sip.ingest(context, dso, tempFile, pparams, license);
}
catch (PackageException e)
{
throw new CrosswalkInternalException(e);
}
}
}