    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}