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.util.Set;
020
021import org.apache.commons.collections4.Bag;
022import org.apache.commons.collections4.collection.SynchronizedCollection;
023import org.apache.commons.collections4.multiset.SynchronizedMultiSet;
024
025/**
026 * Decorates another {@link Bag} to synchronize its behavior
027 * for a multithreaded environment.
028 * <p>
029 * Methods are synchronized, then forwarded to the decorated bag.
030 * Iterators must be separately synchronized around the loop.
031 * </p>
032 * <p>
033 * This class is Serializable from Commons Collections 3.1.
034 * </p>
035 *
036 * @param <E> The type of elements in this bag
037 * @since 3.0
038 * @deprecated Since 4.6.0, use {@link SynchronizedMultiSet} instead.
039 */
040@Deprecated
041public class SynchronizedBag<E> extends SynchronizedCollection<E> implements Bag<E> {
042
043    /**
044     * Synchronized Set for the Bag class.
045     */
046    final class SynchronizedBagSet extends SynchronizedCollection<E> implements Set<E> {
047
048        /** Serialization version */
049        private static final long serialVersionUID = 2990565892366827855L;
050
051        /**
052         * Constructs a new instance.
053         *
054         * @param set  The set to decorate
055         * @param lock  The lock to use, shared with the bag
056         */
057        SynchronizedBagSet(final Set<E> set, final Object lock) {
058            super(set, lock);
059        }
060    }
061
062    /** Serialization version */
063    private static final long serialVersionUID = 8084674570753837109L;
064
065    /**
066     * Factory method to create a synchronized bag.
067     *
068     * @param <E> The type of the elements in the bag
069     * @param bag  The bag to decorate, must not be null
070     * @return A new synchronized Bag
071     * @throws NullPointerException if bag is null
072     * @since 4.0
073     */
074    public static <E> SynchronizedBag<E> synchronizedBag(final Bag<E> bag) {
075        return new SynchronizedBag<>(bag);
076    }
077
078    /**
079     * Constructor that wraps (not copies).
080     *
081     * @param bag  The bag to decorate, must not be null
082     * @throws NullPointerException if bag is null
083     */
084    protected SynchronizedBag(final Bag<E> bag) {
085        super(bag);
086    }
087
088    /**
089     * Constructor that wraps (not copies).
090     *
091     * @param bag  The bag to decorate, must not be null
092     * @param lock  The lock to use, must not be null
093     * @throws NullPointerException if bag or lock is null
094     */
095    protected SynchronizedBag(final Bag<E> bag, final Object lock) {
096        super(bag, lock);
097    }
098
099    @Override
100    public boolean add(final E object, final int count) {
101        synchronized (lock) {
102            return getBag().add(object, count);
103        }
104    }
105
106    @Override
107    public boolean equals(final Object object) {
108        if (object == this) {
109            return true;
110        }
111        synchronized (lock) {
112            return getBag().equals(object);
113        }
114    }
115
116    /**
117     * Gets the bag being decorated.
118     *
119     * @return The decorated bag
120     */
121    protected Bag<E> getBag() {
122        return (Bag<E>) decorated();
123    }
124
125    @Override
126    public int getCount(final Object object) {
127        synchronized (lock) {
128            return getBag().getCount(object);
129        }
130    }
131
132    @Override
133    public int hashCode() {
134        synchronized (lock) {
135            return getBag().hashCode();
136        }
137    }
138
139    @Override
140    public boolean remove(final Object object, final int count) {
141        synchronized (lock) {
142            return getBag().remove(object, count);
143        }
144    }
145
146    @Override
147    public Set<E> uniqueSet() {
148        synchronized (lock) {
149            final Set<E> set = getBag().uniqueSet();
150            return new SynchronizedBagSet(set, lock);
151        }
152    }
153
154}