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.Transformer;
021 import org.apache.commons.collections.collection.TransformedCollection;
022
023 /**
024 * Decorates another <code>Buffer</code> to transform objects that are added.
025 * <p>
026 * The add methods are affected by this class.
027 * Thus objects must be removed or searched for using their transformed form.
028 * For example, if the transformation converts Strings to Integers, you must
029 * use the Integer form to remove objects.
030 * <p>
031 * This class is Serializable from Commons Collections 3.1.
032 *
033 * @since Commons Collections 3.0
034 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
035 *
036 * @author Stephen Colebourne
037 */
038 public class TransformedBuffer extends TransformedCollection implements Buffer {
039
040 /** Serialization version */
041 private static final long serialVersionUID = -7901091318986132033L;
042
043 /**
044 * Factory method to create a transforming buffer.
045 * <p>
046 * If there are any elements already in the buffer being decorated, they
047 * are NOT transformed.
048 *
049 * @param buffer the buffer to decorate, must not be null
050 * @param transformer the transformer to use for conversion, must not be null
051 * @return a new transformed Buffer
052 * @throws IllegalArgumentException if buffer or transformer is null
053 */
054 public static Buffer decorate(Buffer buffer, Transformer transformer) {
055 return new TransformedBuffer(buffer, transformer);
056 }
057
058 //-----------------------------------------------------------------------
059 /**
060 * Constructor that wraps (not copies).
061 * <p>
062 * If there are any elements already in the buffer being decorated, they
063 * are NOT transformed.
064 *
065 * @param buffer the buffer to decorate, must not be null
066 * @param transformer the transformer to use for conversion, must not be null
067 * @throws IllegalArgumentException if buffer or transformer is null
068 */
069 protected TransformedBuffer(Buffer buffer, Transformer transformer) {
070 super(buffer, transformer);
071 }
072
073 /**
074 * Gets the decorated buffer.
075 *
076 * @return the decorated buffer
077 */
078 protected Buffer getBuffer() {
079 return (Buffer) collection;
080 }
081
082 //-----------------------------------------------------------------------
083 public Object get() {
084 return getBuffer().get();
085 }
086
087 public Object remove() {
088 return getBuffer().remove();
089 }
090
091 }