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