/*
* Copyright 2003-2004 The Apache Software Foundation
*
* Licensed 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.set;
import java.util.Comparator;
import java.util.SortedSet;
import org.apache.commons.collections.collection.SynchronizedCollection;
/**
* Decorates another <code>SortedSet</code> to synchronize its behaviour
* for a multi-threaded environment.
* <p>
* Methods are synchronized, then forwarded to the decorated set.
* <p>
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @author Stephen Colebourne
*/
public class SynchronizedSortedSet extends SynchronizedCollection implements SortedSet {
/** Serialization version */
private static final long serialVersionUID = 2775582861954500111L;
/**
* Factory method to create a synchronized set.
*
* @param set the set to decorate, must not be null
* @throws IllegalArgumentException if set is null
*/
public static SortedSet decorate(SortedSet set) {
return new SynchronizedSortedSet(set);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param set the set to decorate, must not be null
* @throws IllegalArgumentException if set is null
*/
protected SynchronizedSortedSet(SortedSet set) {
super(set);
}
/**
* Constructor that wraps (not copies).
*
* @param set the set to decorate, must not be null
* @param lock the lock object to use, must not be null
* @throws IllegalArgumentException if set is null
*/
protected SynchronizedSortedSet(SortedSet set, Object lock) {
super(set, lock);
}
/**
* Gets the decorated set.
*
* @return the decorated set
*/
protected SortedSet getSortedSet() {
return (SortedSet) collection;
}
//-----------------------------------------------------------------------
public SortedSet subSet(Object fromElement, Object toElement) {
synchronized (lock) {
SortedSet set = getSortedSet().subSet(fromElement, toElement);
// the lock is passed into the constructor here to ensure that the
// subset is synchronized on the same lock as the parent
return new SynchronizedSortedSet(set, lock);
}
}
public SortedSet headSet(Object toElement) {
synchronized (lock) {
SortedSet set = getSortedSet().headSet(toElement);
// the lock is passed into the constructor here to ensure that the
// headset is synchronized on the same lock as the parent
return new SynchronizedSortedSet(set, lock);
}
}
public SortedSet tailSet(Object fromElement) {
synchronized (lock) {
SortedSet set = getSortedSet().tailSet(fromElement);
// the lock is passed into the constructor here to ensure that the
// tailset is synchronized on the same lock as the parent
return new SynchronizedSortedSet(set, lock);
}
}
public Object first() {
synchronized (lock) {
return getSortedSet().first();
}
}
public Object last() {
synchronized (lock) {
return getSortedSet().last();
}
}
public Comparator comparator() {
synchronized (lock) {
return getSortedSet().comparator();
}
}
}