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.io.IOException;
020 import java.io.ObjectInputStream;
021 import java.io.ObjectOutputStream;
022 import java.io.Serializable;
023 import java.util.Collection;
024 import java.util.Map;
025 import java.util.Set;
026
027 import org.apache.commons.collections.IterableMap;
028 import org.apache.commons.collections.MapIterator;
029 import org.apache.commons.collections.Unmodifiable;
030 import org.apache.commons.collections.collection.UnmodifiableCollection;
031 import org.apache.commons.collections.iterators.EntrySetMapIterator;
032 import org.apache.commons.collections.iterators.UnmodifiableMapIterator;
033 import org.apache.commons.collections.set.UnmodifiableSet;
034
035 /**
036 * Decorates another <code>Map</code> to ensure it can't be altered.
037 * <p>
038 * This class is Serializable from Commons Collections 3.1.
039 *
040 * @since Commons Collections 3.0
041 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
042 *
043 * @author Stephen Colebourne
044 */
045 public final class UnmodifiableMap
046 extends AbstractMapDecorator
047 implements IterableMap, Unmodifiable, Serializable {
048
049 /** Serialization version */
050 private static final long serialVersionUID = 2737023427269031941L;
051
052 /**
053 * Factory method to create an unmodifiable map.
054 *
055 * @param map the map to decorate, must not be null
056 * @throws IllegalArgumentException if map is null
057 */
058 public static Map decorate(Map map) {
059 if (map instanceof Unmodifiable) {
060 return map;
061 }
062 return new UnmodifiableMap(map);
063 }
064
065 //-----------------------------------------------------------------------
066 /**
067 * Constructor that wraps (not copies).
068 *
069 * @param map the map to decorate, must not be null
070 * @throws IllegalArgumentException if map is null
071 */
072 private UnmodifiableMap(Map map) {
073 super(map);
074 }
075
076 //-----------------------------------------------------------------------
077 /**
078 * Write the map out using a custom routine.
079 *
080 * @param out the output stream
081 * @throws IOException
082 * @since Commons Collections 3.1
083 */
084 private void writeObject(ObjectOutputStream out) throws IOException {
085 out.defaultWriteObject();
086 out.writeObject(map);
087 }
088
089 /**
090 * Read the map in using a custom routine.
091 *
092 * @param in the input stream
093 * @throws IOException
094 * @throws ClassNotFoundException
095 * @since Commons Collections 3.1
096 */
097 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
098 in.defaultReadObject();
099 map = (Map) in.readObject();
100 }
101
102 //-----------------------------------------------------------------------
103 public void clear() {
104 throw new UnsupportedOperationException();
105 }
106
107 public Object put(Object key, Object value) {
108 throw new UnsupportedOperationException();
109 }
110
111 public void putAll(Map mapToCopy) {
112 throw new UnsupportedOperationException();
113 }
114
115 public Object remove(Object key) {
116 throw new UnsupportedOperationException();
117 }
118
119 public MapIterator mapIterator() {
120 if (map instanceof IterableMap) {
121 MapIterator it = ((IterableMap) map).mapIterator();
122 return UnmodifiableMapIterator.decorate(it);
123 } else {
124 MapIterator it = new EntrySetMapIterator(map);
125 return UnmodifiableMapIterator.decorate(it);
126 }
127 }
128
129 public Set entrySet() {
130 Set set = super.entrySet();
131 return UnmodifiableEntrySet.decorate(set);
132 }
133
134 public Set keySet() {
135 Set set = super.keySet();
136 return UnmodifiableSet.decorate(set);
137 }
138
139 public Collection values() {
140 Collection coll = super.values();
141 return UnmodifiableCollection.decorate(coll);
142 }
143
144 }