org.apache.commons.collections.bag.SynchronizedBag Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.commons.collections.bag;
import java.util.Set;
import org.apache.commons.collections.Bag;
import org.apache.commons.collections.collection.SynchronizedCollection;
import org.apache.commons.collections.set.SynchronizedSet;
/**
* 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.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
*/
public class SynchronizedBag
extends SynchronizedCollection implements Bag {
/** Serialization version */
private static final long serialVersionUID = 8084674570753837109L;
/**
* Factory method to create a synchronized bag.
*
* @param bag the bag to decorate, must not be null
* @return a new synchronized Bag
* @throws IllegalArgumentException if bag is null
*/
public static Bag decorate(Bag bag) {
return new SynchronizedBag(bag);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param bag the bag to decorate, must not be null
* @throws IllegalArgumentException if bag is null
*/
protected SynchronizedBag(Bag bag) {
super(bag);
}
/**
* 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 IllegalArgumentException if bag is null
*/
protected SynchronizedBag(Bag bag, Object lock) {
super(bag, lock);
}
/**
* Gets the bag being decorated.
*
* @return the decorated bag
*/
protected Bag getBag() {
return (Bag) collection;
}
//-----------------------------------------------------------------------
public boolean add(Object object, int count) {
synchronized (lock) {
return getBag().add(object, count);
}
}
public boolean remove(Object object, int count) {
synchronized (lock) {
return getBag().remove(object, count);
}
}
public Set uniqueSet() {
synchronized (lock) {
Set set = getBag().uniqueSet();
return new SynchronizedBagSet(set, lock);
}
}
public int getCount(Object object) {
synchronized (lock) {
return getBag().getCount(object);
}
}
//-----------------------------------------------------------------------
/**
* Synchronized Set for the Bag class.
*/
class SynchronizedBagSet extends SynchronizedSet {
/**
* Constructor.
* @param set the set to decorate
* @param lock the lock to use, shared with the bag
*/
SynchronizedBagSet(Set set, Object lock) {
super(set, lock);
}
}
}