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 *      https://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.bidimap;
018
019import java.util.Map;
020import java.util.Set;
021
022import org.apache.commons.collections4.OrderedBidiMap;
023import org.apache.commons.collections4.OrderedMapIterator;
024import org.apache.commons.collections4.Unmodifiable;
025import org.apache.commons.collections4.iterators.UnmodifiableOrderedMapIterator;
026import org.apache.commons.collections4.map.UnmodifiableEntrySet;
027import org.apache.commons.collections4.set.UnmodifiableSet;
028
029/**
030 * Decorates another {@link OrderedBidiMap} to ensure it can't be altered.
031 * <p>
032 * Attempts to modify it will result in an UnsupportedOperationException.
033 * </p>
034 *
035 * @param <K> The type of the keys in this map
036 * @param <V> The type of the values in this map
037 * @since 3.0
038 */
039public final class UnmodifiableOrderedBidiMap<K, V>
040        extends AbstractOrderedBidiMapDecorator<K, V> implements Unmodifiable {
041
042    /**
043     * Factory method to create an unmodifiable map.
044     * <p>
045     * If the map passed in is already unmodifiable, it is returned.
046     *
047     * @param <K> The key type
048     * @param <V> The value type
049     * @param map  The map to decorate, must not be null
050     * @return An unmodifiable OrderedBidiMap
051     * @throws NullPointerException if map is null
052     * @since 4.0
053     */
054    public static <K, V> OrderedBidiMap<K, V> unmodifiableOrderedBidiMap(
055            final OrderedBidiMap<? extends K, ? extends V> map) {
056        if (map instanceof Unmodifiable) {
057            @SuppressWarnings("unchecked") // safe to upcast
058            final OrderedBidiMap<K, V> tmpMap = (OrderedBidiMap<K, V>) map;
059            return tmpMap;
060        }
061        return new UnmodifiableOrderedBidiMap<>(map);
062    }
063
064    /** The inverse unmodifiable map */
065    private UnmodifiableOrderedBidiMap<V, K> inverse;
066
067    /**
068     * Constructor that wraps (not copies).
069     *
070     * @param map  The map to decorate, must not be null
071     * @throws NullPointerException if map is null
072     */
073    @SuppressWarnings("unchecked") // safe to upcast
074    private UnmodifiableOrderedBidiMap(final OrderedBidiMap<? extends K, ? extends V> map) {
075        super((OrderedBidiMap<K, V>) map);
076    }
077
078    /**
079     * Always throws {@link UnsupportedOperationException}.
080     *
081     * @throws UnsupportedOperationException Always thrown.
082     */
083    @Override
084    public void clear() {
085        throw new UnsupportedOperationException();
086    }
087
088    @Override
089    public Set<Map.Entry<K, V>> entrySet() {
090        final Set<Map.Entry<K, V>> set = super.entrySet();
091        return UnmodifiableEntrySet.unmodifiableEntrySet(set);
092    }
093
094    @Override
095    public OrderedBidiMap<V, K> inverseBidiMap() {
096        return inverseOrderedBidiMap();
097    }
098
099    /**
100     * Gets an unmodifiable view of this map where the keys and values are reversed.
101     *
102     * @return An inverted unmodifiable bidirectional map
103     */
104    public OrderedBidiMap<V, K> inverseOrderedBidiMap() {
105        if (inverse == null) {
106            inverse = new UnmodifiableOrderedBidiMap<>(decorated().inverseBidiMap());
107            inverse.inverse = this;
108        }
109        return inverse;
110    }
111
112    @Override
113    public Set<K> keySet() {
114        final Set<K> set = super.keySet();
115        return UnmodifiableSet.unmodifiableSet(set);
116    }
117
118    @Override
119    public OrderedMapIterator<K, V> mapIterator() {
120        final OrderedMapIterator<K, V> it = decorated().mapIterator();
121        return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
122    }
123
124    /**
125     * Always throws {@link UnsupportedOperationException}.
126     *
127     * @param key Ignored.
128     * @param value Ignored.
129     * @throws UnsupportedOperationException Always thrown.
130     */
131    @Override
132    public V put(final K key, final V value) {
133        throw new UnsupportedOperationException();
134    }
135
136    /**
137     * Always throws {@link UnsupportedOperationException}.
138     *
139     * @param mapToCopy Ignored.
140     * @throws UnsupportedOperationException Always thrown.
141     */
142    @Override
143    public void putAll(final Map<? extends K, ? extends V> mapToCopy) {
144        throw new UnsupportedOperationException();
145    }
146
147    /**
148     * Always throws {@link UnsupportedOperationException}.
149     *
150     * @param key Ignored.
151     * @throws UnsupportedOperationException Always thrown.
152     */
153    @Override
154    public V remove(final Object key) {
155        throw new UnsupportedOperationException();
156    }
157
158    /**
159     * Always throws {@link UnsupportedOperationException}.
160     *
161     * @param value Ignored.
162     * @throws UnsupportedOperationException Always thrown.
163     */
164    @Override
165    public K removeValue(final Object value) {
166        throw new UnsupportedOperationException();
167    }
168
169    @Override
170    public Set<V> values() {
171        return UnmodifiableSet.unmodifiableSet(super.values());
172    }
173
174}