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 */
017package org.apache.commons.collections4.map;
018
019import java.io.IOException;
020import java.io.ObjectInputStream;
021import java.io.ObjectOutputStream;
022import java.io.Serializable;
023import java.util.Collection;
024import java.util.Map;
025import java.util.Set;
026
027import org.apache.commons.collections4.OrderedMap;
028import org.apache.commons.collections4.OrderedMapIterator;
029import org.apache.commons.collections4.Unmodifiable;
030import org.apache.commons.collections4.collection.UnmodifiableCollection;
031import org.apache.commons.collections4.iterators.UnmodifiableOrderedMapIterator;
032import org.apache.commons.collections4.set.UnmodifiableSet;
033
034/**
035 * Decorates another <code>OrderedMap</code> to ensure it can't be altered.
036 * <p>
037 * This class is Serializable from Commons Collections 3.1.
038 * <p>
039 * Attempts to modify it will result in an UnsupportedOperationException.
040 *
041 * @param <K> the type of the keys in this map
042 * @param <V> the type of the values in this map
043 * @since 3.0
044 */
045public final class UnmodifiableOrderedMap<K, V> extends AbstractOrderedMapDecorator<K, V> implements
046        Unmodifiable, Serializable {
047
048    /** Serialization version */
049    private static final long serialVersionUID = 8136428161720526266L;
050
051    /**
052     * Factory method to create an unmodifiable sorted map.
053     *
054     * @param <K>  the key type
055     * @param <V>  the value type
056     * @param map  the map to decorate, must not be null
057     * @return a new ordered map
058     * @throws NullPointerException if map is null
059     * @since 4.0
060     */
061    public static <K, V> OrderedMap<K, V> unmodifiableOrderedMap(final OrderedMap<? extends K, ? extends V> map) {
062        if (map instanceof Unmodifiable) {
063            @SuppressWarnings("unchecked") // safe to upcast
064            final OrderedMap<K, V> tmpMap = (OrderedMap<K, V>) map;
065            return tmpMap;
066        }
067        return new UnmodifiableOrderedMap<>(map);
068    }
069
070    //-----------------------------------------------------------------------
071    /**
072     * Constructor that wraps (not copies).
073     *
074     * @param map  the map to decorate, must not be null
075     * @throws NullPointerException if map is null
076     */
077    @SuppressWarnings("unchecked") // safe to upcast
078    private UnmodifiableOrderedMap(final OrderedMap<? extends K, ? extends V> map) {
079        super((OrderedMap<K, V>) map);
080    }
081
082    //-----------------------------------------------------------------------
083    /**
084     * Write the map out using a custom routine.
085     *
086     * @param out  the output stream
087     * @throws IOException if an error occurs while writing to the stream
088     * @since 3.1
089     */
090    private void writeObject(final ObjectOutputStream out) throws IOException {
091        out.defaultWriteObject();
092        out.writeObject(map);
093    }
094
095    /**
096     * Read the map in using a custom routine.
097     *
098     * @param in  the input stream
099     * @throws IOException if an error occurs while reading from the stream
100     * @throws ClassNotFoundException if an object read from the stream can not be loaded
101     * @since 3.1
102     */
103    @SuppressWarnings("unchecked") // (1) should only fail if input stream is incorrect
104    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
105        in.defaultReadObject();
106        map = (Map<K, V>) in.readObject(); // (1)
107    }
108
109    //-----------------------------------------------------------------------
110    @Override
111    public OrderedMapIterator<K, V> mapIterator() {
112        final OrderedMapIterator<K, V> it = decorated().mapIterator();
113        return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
114    }
115
116    @Override
117    public void clear() {
118        throw new UnsupportedOperationException();
119    }
120
121    @Override
122    public V put(final K key, final V value) {
123        throw new UnsupportedOperationException();
124    }
125
126    @Override
127    public void putAll(final Map<? extends K, ? extends V> mapToCopy) {
128        throw new UnsupportedOperationException();
129    }
130
131    @Override
132    public V remove(final Object key) {
133        throw new UnsupportedOperationException();
134    }
135
136    @Override
137    public Set<Map.Entry<K, V>> entrySet() {
138        final Set<Map.Entry<K, V>> set = super.entrySet();
139        return UnmodifiableEntrySet.unmodifiableEntrySet(set);
140    }
141
142    @Override
143    public Set<K> keySet() {
144        final Set<K> set = super.keySet();
145        return UnmodifiableSet.unmodifiableSet(set);
146    }
147
148    @Override
149    public Collection<V> values() {
150        final Collection<V> coll = super.values();
151        return UnmodifiableCollection.unmodifiableCollection(coll);
152    }
153
154}