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}