/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package org.apache.commons.collections4.bag;

import java.util.Set;

import org.apache.commons.collections4.Bag;
import org.apache.commons.collections4.collection.SynchronizedCollection;

Decorates another Bag to synchronize its behaviour for a multi-threaded environment.

Methods are synchronized, then forwarded to the decorated bag. Iterators must be separately synchronized around the loop.

This class is Serializable from Commons Collections 3.1.

Type parameters:
  • <E> – the type of elements in this bag
Since:3.0
/** * Decorates another {@link Bag} to synchronize its behaviour * for a multi-threaded environment. * <p> * Methods are synchronized, then forwarded to the decorated bag. * Iterators must be separately synchronized around the loop. * <p> * This class is Serializable from Commons Collections 3.1. * * @param <E> the type of elements in this bag * @since 3.0 */
public class SynchronizedBag<E> extends SynchronizedCollection<E> implements Bag<E> {
Serialization version
/** Serialization version */
private static final long serialVersionUID = 8084674570753837109L;
Factory method to create a synchronized bag.
Params:
  • bag – the bag to decorate, must not be null
Type parameters:
  • <E> – the type of the elements in the bag
Throws:
Returns:a new synchronized Bag
Since:4.0
/** * Factory method to create a synchronized bag. * * @param <E> the type of the elements in the bag * @param bag the bag to decorate, must not be null * @return a new synchronized Bag * @throws NullPointerException if bag is null * @since 4.0 */
public static <E> SynchronizedBag<E> synchronizedBag(final Bag<E> bag) { return new SynchronizedBag<>(bag); } //-----------------------------------------------------------------------
Constructor that wraps (not copies).
Params:
  • bag – the bag to decorate, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param bag the bag to decorate, must not be null * @throws NullPointerException if bag is null */
protected SynchronizedBag(final Bag<E> bag) { super(bag); }
Constructor that wraps (not copies).
Params:
  • bag – the bag to decorate, must not be null
  • lock – the lock to use, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param bag the bag to decorate, must not be null * @param lock the lock to use, must not be null * @throws NullPointerException if bag or lock is null */
protected SynchronizedBag(final Bag<E> bag, final Object lock) { super(bag, lock); }
Gets the bag being decorated.
Returns:the decorated bag
/** * Gets the bag being decorated. * * @return the decorated bag */
protected Bag<E> getBag() { return (Bag<E>) decorated(); } @Override public boolean equals(final Object object) { if (object == this) { return true; } synchronized (lock) { return getBag().equals(object); } } @Override public int hashCode() { synchronized (lock) { return getBag().hashCode(); } } //----------------------------------------------------------------------- @Override public boolean add(final E object, final int count) { synchronized (lock) { return getBag().add(object, count); } } @Override public boolean remove(final Object object, final int count) { synchronized (lock) { return getBag().remove(object, count); } } @Override public Set<E> uniqueSet() { synchronized (lock) { final Set<E> set = getBag().uniqueSet(); return new SynchronizedBagSet(set, lock); } } @Override public int getCount(final Object object) { synchronized (lock) { return getBag().getCount(object); } } //-----------------------------------------------------------------------
Synchronized Set for the Bag class.
/** * Synchronized Set for the Bag class. */
class SynchronizedBagSet extends SynchronizedCollection<E> implements Set<E> {
Serialization version
/** Serialization version */
private static final long serialVersionUID = 2990565892366827855L;
Constructor.
Params:
  • set – the set to decorate
  • lock – the lock to use, shared with the bag
/** * Constructor. * @param set the set to decorate * @param lock the lock to use, shared with the bag */
SynchronizedBagSet(final Set<E> set, final Object lock) { super(set, lock); } } }