001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.commons.collections.map;
018    
019    import java.util.Comparator;
020    import java.util.SortedMap;
021    
022    import org.apache.commons.collections.Predicate;
023    
024    /**
025     * Decorates another <code>SortedMap </code> to validate that additions
026     * match a specified predicate.
027     * <p>
028     * This map exists to provide validation for the decorated map.
029     * It is normally created to decorate an empty map.
030     * If an object cannot be added to the map, an IllegalArgumentException is thrown.
031     * <p>
032     * One usage would be to ensure that no null keys are added to the map.
033     * <pre>SortedMap map = PredicatedSortedSet.decorate(new TreeMap(), NotNullPredicate.INSTANCE, null);</pre>
034     * <p>
035     * <strong>Note that PredicatedSortedMap is not synchronized and is not thread-safe.</strong>
036     * If you wish to use this map from multiple threads concurrently, you must use
037     * appropriate synchronization. The simplest approach is to wrap this map
038     * using {@link java.util.Collections#synchronizedSortedMap}. This class may throw 
039     * exceptions when accessed by concurrent threads without synchronization.
040     * <p>
041     * This class is Serializable from Commons Collections 3.1.
042     *
043     * @since Commons Collections 3.0
044     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
045     * 
046     * @author Stephen Colebourne
047     * @author Paul Jack
048     */
049    public class PredicatedSortedMap
050            extends PredicatedMap
051            implements SortedMap {
052    
053        /** Serialization version */
054        private static final long serialVersionUID = 3359846175935304332L;
055    
056        /**
057         * Factory method to create a predicated (validating) sorted map.
058         * <p>
059         * If there are any elements already in the list being decorated, they
060         * are validated.
061         * 
062         * @param map  the map to decorate, must not be null
063         * @param keyPredicate  the predicate to validate the keys, null means no check
064         * @param valuePredicate  the predicate to validate to values, null means no check
065         * @throws IllegalArgumentException if the map is null
066         */
067        public static SortedMap decorate(SortedMap map, Predicate keyPredicate, Predicate valuePredicate) {
068            return new PredicatedSortedMap(map, keyPredicate, valuePredicate);
069        }
070    
071        //-----------------------------------------------------------------------
072        /**
073         * Constructor that wraps (not copies).
074         * 
075         * @param map  the map to decorate, must not be null
076         * @param keyPredicate  the predicate to validate the keys, null means no check
077         * @param valuePredicate  the predicate to validate to values, null means no check
078         * @throws IllegalArgumentException if the map is null
079         */
080        protected PredicatedSortedMap(SortedMap map, Predicate keyPredicate, Predicate valuePredicate) {
081            super(map, keyPredicate, valuePredicate);
082        }
083    
084        //-----------------------------------------------------------------------
085        /**
086         * Gets the map being decorated.
087         * 
088         * @return the decorated map
089         */
090        protected SortedMap getSortedMap() {
091            return (SortedMap) map;
092        }
093    
094        //-----------------------------------------------------------------------
095        public Object firstKey() {
096            return getSortedMap().firstKey();
097        }
098    
099        public Object lastKey() {
100            return getSortedMap().lastKey();
101        }
102    
103        public Comparator comparator() {
104            return getSortedMap().comparator();
105        }
106    
107        public SortedMap subMap(Object fromKey, Object toKey) {
108            SortedMap map = getSortedMap().subMap(fromKey, toKey);
109            return new PredicatedSortedMap(map, keyPredicate, valuePredicate);
110        }
111    
112        public SortedMap headMap(Object toKey) {
113            SortedMap map = getSortedMap().headMap(toKey);
114            return new PredicatedSortedMap(map, keyPredicate, valuePredicate);
115        }
116    
117        public SortedMap tailMap(Object fromKey) {
118            SortedMap map = getSortedMap().tailMap(fromKey);
119            return new PredicatedSortedMap(map, keyPredicate, valuePredicate);
120        }
121    
122    }