    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.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    @Override
    079    public void clear() {
    080        throw new UnsupportedOperationException();
    081    }
    082
    083    @Override
    084    public Set<Map.Entry<K, V>> entrySet() {
    085        final Set<Map.Entry<K, V>> set = super.entrySet();
    086        return UnmodifiableEntrySet.unmodifiableEntrySet(set);
    087    }
    088
    089    @Override
    090    public OrderedBidiMap<V, K> inverseBidiMap() {
    091        return inverseOrderedBidiMap();
    092    }
    093
    094    /**
    095     * Gets an unmodifiable view of this map where the keys and values are reversed.
    096     *
    097     * @return an inverted unmodifiable bidirectional map
    098     */
    099    public OrderedBidiMap<V, K> inverseOrderedBidiMap() {
    100        if (inverse == null) {
    101            inverse = new UnmodifiableOrderedBidiMap<>(decorated().inverseBidiMap());
    102            inverse.inverse = this;
    103        }
    104        return inverse;
    105    }
    106
    107    @Override
    108    public Set<K> keySet() {
    109        final Set<K> set = super.keySet();
    110        return UnmodifiableSet.unmodifiableSet(set);
    111    }
    112
    113    @Override
    114    public OrderedMapIterator<K, V> mapIterator() {
    115        final OrderedMapIterator<K, V> it = decorated().mapIterator();
    116        return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
    117    }
    118
    119    @Override
    120    public V put(final K key, final V value) {
    121        throw new UnsupportedOperationException();
    122    }
    123
    124    @Override
    125    public void putAll(final Map<? extends K, ? extends V> mapToCopy) {
    126        throw new UnsupportedOperationException();
    127    }
    128
    129    @Override
    130    public V remove(final Object key) {
    131        throw new UnsupportedOperationException();
    132    }
    133
    134    @Override
    135    public K removeValue(final Object value) {
    136        throw new UnsupportedOperationException();
    137    }
    138
    139    @Override
    140    public Set<V> values() {
    141        final Set<V> set = super.values();
    142        return UnmodifiableSet.unmodifiableSet(set);
    143    }
    144
    145}