/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2001-2012, Open Source Geospatial Foundation (OSGeo)
* (C) 2009-2012, 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.
*
* This package contains documentation from OpenGIS specifications.
* OpenGIS consortium's work is fully acknowledged here.
*/
package org.geotoolkit.referencing;
import java.util.Iterator;
import java.util.Comparator;
import java.util.Collection;
import java.util.Collections;
import java.io.Serializable;
import java.io.ObjectStreamException;
import org.opengis.referencing.IdentifiedObject;
import org.opengis.metadata.Identifier;
/**
* {@link IdentifiedObjects#IDENTIFIER_COMPARATOR} implementation as a named class (rather than anonymous)
* for more predictable serialization.
*
* @author Martin Desruisseaux (IRD, Geomatys)
* @version 3.20
*
* @since 3.20 (derived from 1.2)
* @module
*/
final class IdentifierComparator implements Comparator<IdentifiedObject>, Serializable {
/** For cross-version compatibility. */
private static final long serialVersionUID = -7315726806679993522L;
/** Compares the given identified objects for order. */
@Override public int compare(final IdentifiedObject o1, final IdentifiedObject o2) {
Collection<Identifier> a1 = o1.getIdentifiers();
Collection<Identifier> a2 = o2.getIdentifiers();
if (a1 == null) a1 = Collections.emptySet();
if (a2 == null) a2 = Collections.emptySet();
final Iterator<Identifier> i1 = a1.iterator();
final Iterator<Identifier> i2 = a2.iterator();
boolean n1, n2;
while ((n1 = i1.hasNext()) & (n2 = i2.hasNext())) { // NOSONAR: Really '&', not '&&'
final int c = IdentifiedObjects.doCompare(i1.next().getCode(), i2.next().getCode());
if (c != 0) {
return c;
}
}
if (n1) return +1;
if (n2) return -1;
return 0;
}
/** Canonicalizes to the singleton on deserialization. */
protected Object readResolve() throws ObjectStreamException {
return IdentifiedObjects.IDENTIFIER_COMPARATOR;
}
}