    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}