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 *  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
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package org.apache.commons.collections.list;

import java.util.Collection;
import java.util.List;
import java.util.ListIterator;

import org.apache.commons.collections.collection.SynchronizedCollection;

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

Methods are synchronized, then forwarded to the decorated list.

This class is Serializable from Commons Collections 3.1.

Author:Stephen Colebourne
Since:Commons Collections 3.0
Version:$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
/** * Decorates another <code>List</code> to synchronize its behaviour * for a multi-threaded environment. * <p> * Methods are synchronized, then forwarded to the decorated list. * <p> * This class is Serializable from Commons Collections 3.1. * * @since Commons Collections 3.0 * @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $ * * @author Stephen Colebourne */
public class SynchronizedList extends SynchronizedCollection implements List {
Serialization version
/** Serialization version */
private static final long serialVersionUID = -1403835447328619437L;
Factory method to create a synchronized list.
Params:
  • list – the list to decorate, must not be null
Throws:
/** * Factory method to create a synchronized list. * * @param list the list to decorate, must not be null * @throws IllegalArgumentException if list is null */
public static List decorate(List list) { return new SynchronizedList(list); } //-----------------------------------------------------------------------
Constructor that wraps (not copies).
Params:
  • list – the list to decorate, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param list the list to decorate, must not be null * @throws IllegalArgumentException if list is null */
protected SynchronizedList(List list) { super(list); }
Constructor that wraps (not copies).
Params:
  • list – the list to decorate, must not be null
  • lock – the lock to use, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param list the list to decorate, must not be null * @param lock the lock to use, must not be null * @throws IllegalArgumentException if list is null */
protected SynchronizedList(List list, Object lock) { super(list, lock); }
Gets the decorated list.
Returns:the decorated list
/** * Gets the decorated list. * * @return the decorated list */
protected List getList() { return (List) collection; } //----------------------------------------------------------------------- public void add(int index, Object object) { synchronized (lock) { getList().add(index, object); } } public boolean addAll(int index, Collection coll) { synchronized (lock) { return getList().addAll(index, coll); } } public Object get(int index) { synchronized (lock) { return getList().get(index); } } public int indexOf(Object object) { synchronized (lock) { return getList().indexOf(object); } } public int lastIndexOf(Object object) { synchronized (lock) { return getList().lastIndexOf(object); } }
Iterators must be manually synchronized.
synchronized (coll) {
  ListIterator it = coll.listIterator();
  // do stuff with iterator
}
Returns:an iterator that must be manually synchronized on the collection
/** * Iterators must be manually synchronized. * <pre> * synchronized (coll) { * ListIterator it = coll.listIterator(); * // do stuff with iterator * } * * @return an iterator that must be manually synchronized on the collection */
public ListIterator listIterator() { return getList().listIterator(); }
Iterators must be manually synchronized.
synchronized (coll) {
  ListIterator it = coll.listIterator(3);
  // do stuff with iterator
}
Returns:an iterator that must be manually synchronized on the collection
/** * Iterators must be manually synchronized. * <pre> * synchronized (coll) { * ListIterator it = coll.listIterator(3); * // do stuff with iterator * } * * @return an iterator that must be manually synchronized on the collection */
public ListIterator listIterator(int index) { return getList().listIterator(index); } public Object remove(int index) { synchronized (lock) { return getList().remove(index); } } public Object set(int index, Object object) { synchronized (lock) { return getList().set(index, object); } } public List subList(int fromIndex, int toIndex) { synchronized (lock) { List list = getList().subList(fromIndex, toIndex); // the lock is passed into the constructor here to ensure that the sublist is // synchronized on the same lock as the parent list return new SynchronizedList(list, lock); } } }