001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.ecm.core.model;
023
024import java.io.Serializable;
025import java.util.Comparator;
026
027/**
028 * Compares documents by paths. Placeless documents (null path) are sorted first, and compared by id between themselves.
029 *
030 * @author <a href="mailto:[email protected]">Georges Racinet</a>
031 */
032public class PathComparator implements Comparator<Document>, Serializable {
033
034    private static final long serialVersionUID = 1L;
035
036    @Override
037    public int compare(Document o1, Document o2) {
038        String p1 = o1.getPath();
039        String p2 = o2.getPath();
040        if (p1 == null && p2 == null) {
041            return o1.getUUID().compareTo(o2.getUUID());
042        }
043        if (p1 == null) {
044            return -1;
045        }
046        if (p2 == null) {
047            return 1;
048        }
049        // The character "/" should be considered as the highest discriminant to
050        // sort paths. So we replace it with the first unicode character
051        return p1.replace("/", "\u0000").compareTo(p2.replace("/", "\u0000"));
052    }
053
054}