org.apache.commons.collections4.bag.SynchronizedSortedBag Maven / Gradle / Ivy
Show all versions of commons-collections4 Show documentation
/*
* 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.collections4.bag;
import java.util.Comparator;
import org.apache.commons.collections4.Bag;
import org.apache.commons.collections4.SortedBag;
/**
* Decorates another {@link SortedBag} 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.
*
* @param the type of elements in this bag
* @since 3.0
*/
public class SynchronizedSortedBag extends SynchronizedBag implements SortedBag {
/** Serialization version */
private static final long serialVersionUID = 722374056718497858L;
/**
* Factory method to create a synchronized sorted bag.
*
* @param the type of the elements in the bag
* @param bag the bag to decorate, must not be null
* @return a new synchronized SortedBag
* @throws NullPointerException if bag is null
* @since 4.0
*/
public static SynchronizedSortedBag synchronizedSortedBag(final SortedBag bag) {
return new SynchronizedSortedBag<>(bag);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param bag the bag to decorate, must not be null
* @throws NullPointerException if bag is null
*/
protected SynchronizedSortedBag(final SortedBag 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 NullPointerException if bag or lock is null
*/
protected SynchronizedSortedBag(final Bag bag, final Object lock) {
super(bag, lock);
}
/**
* Gets the bag being decorated.
*
* @return the decorated bag
*/
protected SortedBag getSortedBag() {
return (SortedBag) decorated();
}
//-----------------------------------------------------------------------
@Override
public synchronized E first() {
synchronized (lock) {
return getSortedBag().first();
}
}
@Override
public synchronized E last() {
synchronized (lock) {
return getSortedBag().last();
}
}
@Override
public synchronized Comparator comparator() {
synchronized (lock) {
return getSortedBag().comparator();
}
}
}