    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.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} to ensure it can't be altered.
    036 * <p>
    037 * This class is Serializable from Commons Collections 3.1.
    038 * </p>
    039 * <p>
    040 * Attempts to modify it will result in an UnsupportedOperationException.
    041 * </p>
    042 *
    043 * @param <K> The type of the keys in this map
    044 * @param <V> The type of the values in this map
    045 * @since 3.0
    046 */
    047public final class UnmodifiableOrderedMap<K, V> extends AbstractOrderedMapDecorator<K, V> implements
    048        Unmodifiable, Serializable {
    049
    050    /** Serialization version */
    051    private static final long serialVersionUID = 8136428161720526266L;
    052
    053    /**
    054     * Factory method to create an unmodifiable sorted map.
    055     *
    056     * @param <K>  the key type
    057     * @param <V>  the value type
    058     * @param map  The map to decorate, must not be null
    059     * @return A new ordered map
    060     * @throws NullPointerException if map is null
    061     * @since 4.0
    062     */
    063    public static <K, V> OrderedMap<K, V> unmodifiableOrderedMap(final OrderedMap<? extends K, ? extends V> map) {
    064        if (map instanceof Unmodifiable) {
    065            @SuppressWarnings("unchecked") // safe to upcast
    066            final OrderedMap<K, V> tmpMap = (OrderedMap<K, V>) map;
    067            return tmpMap;
    068        }
    069        return new UnmodifiableOrderedMap<>(map);
    070    }
    071
    072    /**
    073     * Constructor that wraps (not copies).
    074     *
    075     * @param map  The map to decorate, must not be null
    076     * @throws NullPointerException if map is null
    077     */
    078    @SuppressWarnings("unchecked") // safe to upcast
    079    private UnmodifiableOrderedMap(final OrderedMap<? extends K, ? extends V> map) {
    080        super((OrderedMap<K, V>) map);
    081    }
    082
    083    /**
    084     * Always throws {@link UnsupportedOperationException}.
    085     *
    086     * @throws UnsupportedOperationException Always thrown.
    087     */
    088    @Override
    089    public void clear() {
    090        throw new UnsupportedOperationException();
    091    }
    092
    093    @Override
    094    public Set<Map.Entry<K, V>> entrySet() {
    095        return UnmodifiableEntrySet.unmodifiableEntrySet(super.entrySet());
    096    }
    097
    098    @Override
    099    public Set<K> keySet() {
    100        return UnmodifiableSet.unmodifiableSet(super.keySet());
    101    }
    102
    103    @Override
    104    public OrderedMapIterator<K, V> mapIterator() {
    105        final OrderedMapIterator<K, V> it = decorated().mapIterator();
    106        return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
    107    }
    108
    109    /**
    110     * Always throws {@link UnsupportedOperationException}.
    111     *
    112     * @param key Ignored.
    113     * @param value Ignored.
    114     * @throws UnsupportedOperationException Always thrown.
    115     */
    116    @Override
    117    public V put(final K key, final V value) {
    118        throw new UnsupportedOperationException();
    119    }
    120
    121    /**
    122     * Always throws {@link UnsupportedOperationException}.
    123     *
    124     * @param mapToCopy Ignored.
    125     * @throws UnsupportedOperationException Always thrown.
    126     */
    127    @Override
    128    public void putAll(final Map<? extends K, ? extends V> mapToCopy) {
    129        throw new UnsupportedOperationException();
    130    }
    131
    132    /**
    133     * Deseializes the map in using a custom routine.
    134     *
    135     * @param in  The input stream
    136     * @throws IOException Thrown if an error occurs while reading from the stream
    137     * @throws ClassNotFoundException if an object read from the stream cannot be loaded
    138     * @since 3.1
    139     */
    140    @SuppressWarnings("unchecked") // (1) should only fail if input stream is incorrect
    141    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
    142        in.defaultReadObject();
    143        map = (Map<K, V>) in.readObject(); // (1)
    144    }
    145
    146    /**
    147     * Always throws {@link UnsupportedOperationException}.
    148     *
    149     * @param key Ignored.
    150     * @throws UnsupportedOperationException Always thrown.
    151     */
    152    @Override
    153    public V remove(final Object key) {
    154        throw new UnsupportedOperationException();
    155    }
    156
    157    @Override
    158    public Collection<V> values() {
    159        return UnmodifiableCollection.unmodifiableCollection(super.values());
    160    }
    161
    162    /**
    163     * Serializes this object to an ObjectOutputStream.
    164     *
    165     * @param out The target ObjectOutputStream.
    166     * @throws IOException thrown when an I/O errors occur writing to the target stream.
    167     * @since 3.1
    168     */
    169    private void writeObject(final ObjectOutputStream out) throws IOException {
    170        out.defaultWriteObject();
    171        out.writeObject(map);
    172    }
    173
    174}