001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.cookie;
029
030import java.io.Serializable;
031import java.util.Comparator;
032
033import org.apache.http.annotation.Contract;
034import org.apache.http.annotation.ThreadingBehavior;
035
036/**
037 * This cookie comparator ensures that multiple cookies satisfying
038 * a common criteria are ordered in the {@code Cookie} header such
039 * that those with more specific Path attributes precede those with
040 * less specific.
041 *
042 * <p>
043 * This comparator assumes that Path attributes of two cookies
044 * path-match a commmon request-URI. Otherwise, the result of the
045 * comparison is undefined.
046 * </p>
047 *
048 *
049 * @since 4.0
050 */
051@Contract(threading = ThreadingBehavior.IMMUTABLE)
052public class CookiePathComparator implements Serializable, Comparator<Cookie> {
053
054    public static final CookiePathComparator INSTANCE = new CookiePathComparator();
055
056    private static final long serialVersionUID = 7523645369616405818L;
057
058    private String normalizePath(final Cookie cookie) {
059        String path = cookie.getPath();
060        if (path == null) {
061            path = "/";
062        }
063        if (!path.endsWith("/")) {
064            path = path + '/';
065        }
066        return path;
067    }
068
069    @Override
070    public int compare(final Cookie c1, final Cookie c2) {
071        final String path1 = normalizePath(c1);
072        final String path2 = normalizePath(c2);
073        if (path1.equals(path2)) {
074            return 0;
075        } else if (path1.startsWith(path2)) {
076            return -1;
077        } else if (path2.startsWith(path1)) {
078            return 1;
079        } else {
080            // Does not really matter
081            return 0;
082        }
083    }
084
085}