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