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