org.geotoolkit.internal.jaxb.gco.ObjectReference Maven / Gradle / Ivy
Show all versions of geotk-xml-base Show documentation
/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2011-2012, Open Source Geospatial Foundation (OSGeo)
* (C) 2011-2012, Geomatys
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotoolkit.internal.jaxb.gco;
import java.util.UUID;
import org.geotoolkit.xml.XLink;
import org.geotoolkit.xml.ObjectLinker;
import org.geotoolkit.xml.IdentifierMap;
import org.geotoolkit.xml.IdentifierSpace;
import org.geotoolkit.xml.IdentifiedObject;
import org.geotoolkit.util.XArrays;
import org.geotoolkit.internal.jaxb.SpecializedIdentifier;
import org.geotoolkit.internal.jaxb.MarshalContext;
/**
* The {@code gco:ObjectReference} XML attribute group is included by all metadata wrappers defined
* in the {@link org.geotoolkit.internal.jaxb.metadata} package. The attributes of interest defined
* in this group are {@code uuidref}, {@code xlink:href}, {@code xlink:role}, {@code xlink:arcrole},
* {@code xlink:title}, {@code xlink:show} and {@code xlink:actuate}.
*
* This {@code gco:ObjectReference} group is complementary to {@code gco:ObjectIdentification},
* which define the {@code id} and {@code uuid} attributes to be supported by all metadata
* implementations in the public {@link org.geotoolkit.metadata.iso} package and sub-packages.
*
* @author Martin Desruisseaux (Geomatys)
* @version 3.19
*
* @see PropertyType
* @see ObjectIdentification
* @see OGC schema
* @see GEOTK-165
*
* @since 3.18
* @module
*/
final class ObjectReference {
/**
* A URN to an external resources, or to an other part of a XML document, or an identifier.
* The {@code uuidref} attribute is used to refer to an XML element that has a corresponding
* {@code uuid} attribute.
*
* @see Usage of uuidref
*/
String anyUUID;
/**
* The {@code xlink} attributes, or {@code null} if none.
*/
XLink xlink;
/**
* The parsed value of {@link #anyUUID}, computed when first needed.
*/
private transient UUID uuid;
/**
* Creates an initially empty object reference.
*/
ObjectReference() {
}
/**
* Creates an object reference initialized to the given value.
*/
ObjectReference(final UUID uuid, final String anyUUID, final XLink link) {
this.uuid = uuid;
this.anyUUID = anyUUID;
this.xlink = link;
}
/**
* Parses the given string as a UUID.
*
* @param anyUUID The string to parse, or {@code null}.
* @return The parsed UUID, or {@code null}.
* @throws IllegalArgumentException If {@code anyUUID} can not be parsed.
*/
static UUID toUUID(final String anyUUID) throws IllegalArgumentException {
return (anyUUID != null) ? MarshalContext.converters().toUUID(anyUUID) : null;
}
/**
* If the given metadata object is null, tries to get an instance from the identifiers
* declared in this {@code ObjectReference}. If the given metadata object is non-null,
* assigns to that object the identifiers declared in this {@code ObjectReference}.
*
* This method is invoked at unmarshalling time.
*
* @param The compile-time type of the {@code type} argument.
* @param type The expected type of the metadata object.
* @param metadata The metadata object, or {@code null}.
* @return A metadata object for the identifiers, or {@code null}
* @throws IllegalArgumentException If the {@link #anyUUID} field can not be parsed.
*/
final T resolve(final Class type, T metadata) throws IllegalArgumentException {
if (uuid == null) {
uuid = toUUID(anyUUID);
}
if (metadata == null) {
final ObjectLinker linker = MarshalContext.linker();
if ((uuid == null || (metadata = linker.resolve(type, uuid )) == null) &&
(xlink == null || (metadata = linker.resolve(type, xlink)) == null))
{
// Failed to find an existing metadata instance.
// Creates an empty instance with the identifiers.
int count = 0;
SpecializedIdentifier[] identifiers = new SpecializedIdentifier[2];
if (uuid != null) identifiers[count++] = new SpecializedIdentifier (IdentifierSpace.UUID, uuid);
if (xlink != null) identifiers[count++] = new SpecializedIdentifier(IdentifierSpace.XLINK, xlink);
identifiers = XArrays.resize(identifiers, count);
metadata = linker.newIdentifiedObject(type, identifiers);
}
} else {
// If principle, the XML should contain a full metadata object OR a uuidref attribute.
// However if both are present, check if the metadata object referenced by uuidref is
// equals to the object we unmarshalled. If it is, then take the existing instance.
if (uuid != null) {
final Object existing = ObjectIdentification.UUIDs.lookup(uuid);
if (metadata.equals(existing)) {
return type.cast(existing);
}
}
if (metadata instanceof IdentifiedObject) {
final IdentifierMap map = ((IdentifiedObject) metadata).getIdentifierMap();
if (uuid != null) new SpecializedIdentifier (IdentifierSpace.UUID, uuid) .putInto(map);
if (xlink != null) new SpecializedIdentifier(IdentifierSpace.XLINK, xlink).putInto(map);
}
}
return metadata;
}
}