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 */ 017package org.apache.commons.collections4.list; 018 019import java.util.Collection; 020import java.util.List; 021import java.util.ListIterator; 022 023import org.apache.commons.collections4.collection.AbstractCollectionDecorator; 024 025/** 026 * Decorates another {@link List} to provide additional behaviour. 027 * <p> 028 * Methods are forwarded directly to the decorated list. 029 * </p> 030 * 031 * @param <E> the type of the elements in the list 032 * @since 3.0 033 */ 034public abstract class AbstractListDecorator<E> extends AbstractCollectionDecorator<E> 035 implements List<E> { 036 037 /** Serialization version--necessary in an abstract class? */ 038 private static final long serialVersionUID = 4500739654952315623L; 039 040 /** 041 * Constructor only used in deserialization, do not use otherwise. 042 * @since 3.1 043 */ 044 protected AbstractListDecorator() { 045 super(); 046 } 047 048 /** 049 * Constructor that wraps (not copies). 050 * 051 * @param list the list to decorate, must not be null 052 * @throws NullPointerException if list is null 053 */ 054 protected AbstractListDecorator(final List<E> list) { 055 super(list); 056 } 057 058 /** 059 * Gets the list being decorated. 060 * 061 * @return the decorated list 062 */ 063 @Override 064 protected List<E> decorated() { 065 return (List<E>) super.decorated(); 066 } 067 068 @Override 069 public boolean equals(final Object object) { 070 return object == this || decorated().equals(object); 071 } 072 073 @Override 074 public int hashCode() { 075 return decorated().hashCode(); 076 } 077 078 //----------------------------------------------------------------------- 079 080 @Override 081 public void add(final int index, final E object) { 082 decorated().add(index, object); 083 } 084 085 @Override 086 public boolean addAll(final int index, final Collection<? extends E> coll) { 087 return decorated().addAll(index, coll); 088 } 089 090 @Override 091 public E get(final int index) { 092 return decorated().get(index); 093 } 094 095 @Override 096 public int indexOf(final Object object) { 097 return decorated().indexOf(object); 098 } 099 100 @Override 101 public int lastIndexOf(final Object object) { 102 return decorated().lastIndexOf(object); 103 } 104 105 @Override 106 public ListIterator<E> listIterator() { 107 return decorated().listIterator(); 108 } 109 110 @Override 111 public ListIterator<E> listIterator(final int index) { 112 return decorated().listIterator(index); 113 } 114 115 @Override 116 public E remove(final int index) { 117 return decorated().remove(index); 118 } 119 120 @Override 121 public E set(final int index, final E object) { 122 return decorated().set(index, object); 123 } 124 125 @Override 126 public List<E> subList(final int fromIndex, final int toIndex) { 127 return decorated().subList(fromIndex, toIndex); 128 } 129 130}