1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.collections4.bag;
18
19 import java.io.IOException;
20 import java.io.ObjectInputStream;
21 import java.io.ObjectOutputStream;
22 import java.util.Collection;
23 import java.util.Iterator;
24 import java.util.Set;
25 import java.util.function.Predicate;
26
27 import org.apache.commons.collections4.Bag;
28 import org.apache.commons.collections4.Unmodifiable;
29 import org.apache.commons.collections4.iterators.UnmodifiableIterator;
30 import org.apache.commons.collections4.multiset.UnmodifiableMultiSet;
31 import org.apache.commons.collections4.set.UnmodifiableSet;
32
33 /**
34 * Decorates another {@link Bag} to ensure it can't be altered.
35 * <p>
36 * This class is Serializable from Commons Collections 3.1.
37 * </p>
38 * <p>
39 * Attempts to modify it will result in an UnsupportedOperationException.
40 * </p>
41 *
42 * @param <E> The type of elements in this bag
43 * @since 3.0
44 * @deprecated Since 4.6.0, use {@link UnmodifiableMultiSet} instead.
45 */
46 @Deprecated
47 public final class UnmodifiableBag<E>
48 extends AbstractBagDecorator<E> implements Unmodifiable {
49
50 /** Serialization version */
51 private static final long serialVersionUID = -1873799975157099624L;
52
53 /**
54 * Factory method to create an unmodifiable bag.
55 * <p>
56 * If the bag passed in is already unmodifiable, it is returned.
57 *
58 * @param <E> The type of the elements in the bag
59 * @param bag The bag to decorate, must not be null
60 * @return An unmodifiable Bag
61 * @throws NullPointerException if bag is null
62 * @since 4.0
63 */
64 public static <E> Bag<E> unmodifiableBag(final Bag<? extends E> bag) {
65 if (bag instanceof Unmodifiable) {
66 @SuppressWarnings("unchecked") // safe to upcast
67 final Bag<E> tmpBag = (Bag<E>) bag;
68 return tmpBag;
69 }
70 return new UnmodifiableBag<>(bag);
71 }
72
73 /**
74 * Constructor that wraps (not copies).
75 *
76 * @param bag The bag to decorate, must not be null
77 * @throws NullPointerException if bag is null
78 */
79 @SuppressWarnings("unchecked") // safe to upcast
80 private UnmodifiableBag(final Bag<? extends E> bag) {
81 super((Bag<E>) bag);
82 }
83
84 /**
85 * Always throws {@link UnsupportedOperationException}.
86 *
87 * @param object Ignored.
88 * @throws UnsupportedOperationException Always thrown.
89 */
90 @Override
91 public boolean add(final E object) {
92 throw new UnsupportedOperationException();
93 }
94
95 /**
96 * Always throws {@link UnsupportedOperationException}.
97 *
98 * @param object Ignored.
99 * @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 }