    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.bag;
    018
    019import java.io.IOException;
    020import java.io.ObjectInputStream;
    021import java.io.ObjectOutputStream;
    022import java.util.Collection;
    023import java.util.Iterator;
    024import java.util.Set;
    025import java.util.function.Predicate;
    026
    027import org.apache.commons.collections4.Bag;
    028import org.apache.commons.collections4.Unmodifiable;
    029import org.apache.commons.collections4.iterators.UnmodifiableIterator;
    030import org.apache.commons.collections4.multiset.UnmodifiableMultiSet;
    031import org.apache.commons.collections4.set.UnmodifiableSet;
    032
    033/**
    034 * Decorates another {@link Bag} to ensure it can't be altered.
    035 * <p>
    036 * This class is Serializable from Commons Collections 3.1.
    037 * </p>
    038 * <p>
    039 * Attempts to modify it will result in an UnsupportedOperationException.
    040 * </p>
    041 *
    042 * @param <E> The type of elements in this bag
    043 * @since 3.0
    044 * @deprecated Since 4.6.0, use {@link UnmodifiableMultiSet} instead.
    045 */
    046@Deprecated
    047public final class UnmodifiableBag<E>
    048        extends AbstractBagDecorator<E> implements Unmodifiable {
    049
    050    /** Serialization version */
    051    private static final long serialVersionUID = -1873799975157099624L;
    052
    053    /**
    054     * Factory method to create an unmodifiable bag.
    055     * <p>
    056     * If the bag passed in is already unmodifiable, it is returned.
    057     *
    058     * @param <E> The type of the elements in the bag
    059     * @param bag  The bag to decorate, must not be null
    060     * @return An unmodifiable Bag
    061     * @throws NullPointerException if bag is null
    062     * @since 4.0
    063     */
    064    public static <E> Bag<E> unmodifiableBag(final Bag<? extends E> bag) {
    065        if (bag instanceof Unmodifiable) {
    066            @SuppressWarnings("unchecked") // safe to upcast
    067            final Bag<E> tmpBag = (Bag<E>) bag;
    068            return tmpBag;
    069        }
    070        return new UnmodifiableBag<>(bag);
    071    }
    072
    073    /**
    074     * Constructor that wraps (not copies).
    075     *
    076     * @param bag  The bag to decorate, must not be null
    077     * @throws NullPointerException if bag is null
    078     */
    079    @SuppressWarnings("unchecked") // safe to upcast
    080    private UnmodifiableBag(final Bag<? extends E> bag) {
    081        super((Bag<E>) bag);
    082    }
    083
    084    /**
    085     * Always throws {@link UnsupportedOperationException}.
    086     *
    087     * @param object Ignored.
    088     * @throws UnsupportedOperationException Always thrown.
    089     */
    090    @Override
    091    public boolean add(final E object) {
    092        throw new UnsupportedOperationException();
    093    }
    094
    095    /**
    096     * Always throws {@link UnsupportedOperationException}.
    097     *
    098     * @param object Ignored.
    099     * @param count Ignored.
    100     * @throws UnsupportedOperationException Always thrown.
    101     */
    102    @Override
    103    public boolean add(final E object, final int count) {
    104        throw new UnsupportedOperationException();
    105    }
    106
    107    /**
    108     * Always throws {@link UnsupportedOperationException}.
    109     *
    110     * @param coll Ignored.
    111     * @throws UnsupportedOperationException Always thrown.
    112     */
    113    @Override
    114    public boolean addAll(final Collection<? extends E> coll) {
    115        throw new UnsupportedOperationException();
    116    }
    117
    118    /**
    119     * Always throws {@link UnsupportedOperationException}.
    120     *
    121     * @throws UnsupportedOperationException Always thrown.
    122     */
    123    @Override
    124    public void clear() {
    125        throw new UnsupportedOperationException();
    126    }
    127
    128    @Override
    129    public Iterator<E> iterator() {
    130        return UnmodifiableIterator.<E>unmodifiableIterator(decorated().iterator());
    131    }
    132
    133    /**
    134     * Deserializes the collection in using a custom routine.
    135     *
    136     * @param in  The input stream
    137     * @throws IOException Thrown if an error occurs while reading from the stream
    138     * @throws ClassNotFoundException if an object read from the stream cannot be loaded
    139     * @throws ClassCastException if deserialized object has wrong type
    140     */
    141    @SuppressWarnings("unchecked") // will throw CCE, see Javadoc
    142    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
    143        in.defaultReadObject();
    144        setCollection((Collection<E>) in.readObject());
    145    }
    146
    147    /**
    148     * Always throws {@link UnsupportedOperationException}.
    149     *
    150     * @param object Ignored.
    151     * @throws UnsupportedOperationException Always thrown.
    152     */
    153    @Override
    154    public boolean remove(final Object object) {
    155        throw new UnsupportedOperationException();
    156    }
    157
    158    /**
    159     * Always throws {@link UnsupportedOperationException}.
    160     *
    161     * @param object Ignored.
    162     * @param count Ignored.
    163     * @throws UnsupportedOperationException Always thrown.
    164     */
    165    @Override
    166    public boolean remove(final Object object, final int count) {
    167        throw new UnsupportedOperationException();
    168    }
    169
    170    /**
    171     * Always throws {@link UnsupportedOperationException}.
    172     *
    173     * @param coll Ignored.
    174     * @throws UnsupportedOperationException Always thrown.
    175     */
    176    @Override
    177    public boolean removeAll(final Collection<?> coll) {
    178        throw new UnsupportedOperationException();
    179    }
    180
    181    /**
    182     * Always throws {@link UnsupportedOperationException}.
    183     *
    184     * @param filter Ignored.
    185     * @throws UnsupportedOperationException Always thrown.
    186     * @since 4.4
    187     */
    188    @Override
    189    public boolean removeIf(final Predicate<? super E> filter) {
    190        throw new UnsupportedOperationException();
    191    }
    192
    193    /**
    194     * Always throws {@link UnsupportedOperationException}.
    195     *
    196     * @param coll Ignored.
    197     * @throws UnsupportedOperationException Always thrown.
    198     */
    199    @Override
    200    public boolean retainAll(final Collection<?> coll) {
    201        throw new UnsupportedOperationException();
    202    }
    203
    204    @Override
    205    public Set<E> uniqueSet() {
    206        return UnmodifiableSet.<E>unmodifiableSet(decorated().uniqueSet());
    207    }
    208
    209    /**
    210     * Serializes this object to an ObjectOutputStream.
    211     *
    212     * @param out The target ObjectOutputStream.
    213     * @throws IOException thrown when an I/O errors occur writing to the target stream.
    214     */
    215    private void writeObject(final ObjectOutputStream out) throws IOException {
    216        out.defaultWriteObject();
    217        out.writeObject(decorated());
    218    }
    219
    220}