001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.commons.collections.buffer;
018    
019    import org.apache.commons.collections.Buffer;
020    import org.apache.commons.collections.collection.SynchronizedCollection;
021    
022    /**
023     * Decorates another <code>Buffer</code> to synchronize its behaviour
024     * for a multi-threaded environment.
025     * <p>
026     * Methods are synchronized, then forwarded to the decorated buffer.
027     * <p>
028     * This class is Serializable from Commons Collections 3.1.
029     *
030     * @since Commons Collections 3.0
031     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
032     * 
033     * @author Stephen Colebourne
034     */
035    public class SynchronizedBuffer extends SynchronizedCollection implements Buffer {
036    
037        /** Serialization version */
038        private static final long serialVersionUID = -6859936183953626253L;
039    
040        /**
041         * Factory method to create a synchronized buffer.
042         * 
043         * @param buffer  the buffer to decorate, must not be null
044         * @return a new synchronized Buffer
045         * @throws IllegalArgumentException if buffer is null
046         */
047        public static Buffer decorate(Buffer buffer) {
048            return new SynchronizedBuffer(buffer);
049        }
050        
051        //-----------------------------------------------------------------------
052        /**
053         * Constructor that wraps (not copies).
054         * 
055         * @param buffer  the buffer to decorate, must not be null
056         * @throws IllegalArgumentException if the buffer is null
057         */
058        protected SynchronizedBuffer(Buffer buffer) {
059            super(buffer);
060        }
061    
062        /**
063         * Constructor that wraps (not copies).
064         * 
065         * @param buffer  the buffer to decorate, must not be null
066         * @param lock  the lock object to use, must not be null
067         * @throws IllegalArgumentException if the buffer is null
068         */
069        protected SynchronizedBuffer(Buffer buffer, Object lock) {
070            super(buffer, lock);
071        }
072    
073        /**
074         * Gets the buffer being decorated.
075         * 
076         * @return the decorated buffer
077         */
078        protected Buffer getBuffer() {
079            return (Buffer) collection;
080        }
081    
082        //-----------------------------------------------------------------------
083        public Object get() {
084            synchronized (lock) {
085                return getBuffer().get();
086            }
087        }
088    
089        public Object remove() {
090            synchronized (lock) {
091                return getBuffer().remove();
092            }
093        }
094        
095    }