    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 behavior.
    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> 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    }
    045
    046    /**
    047     * Constructor that wraps (not copies).
    048     *
    049     * @param list  the list to decorate, must not be null
    050     * @throws NullPointerException if list is null
    051     */
    052    protected AbstractListDecorator(final List<E> list) {
    053        super(list);
    054    }
    055
    056    @Override
    057    public void add(final int index, final E object) {
    058        decorated().add(index, object);
    059    }
    060
    061    @Override
    062    public boolean addAll(final int index, final Collection<? extends E> coll) {
    063        return decorated().addAll(index, coll);
    064    }
    065
    066    /**
    067     * Gets the list being decorated.
    068     *
    069     * @return the decorated list
    070     */
    071    @Override
    072    protected List<E> decorated() {
    073        return (List<E>) super.decorated();
    074    }
    075
    076    @Override
    077    public boolean equals(final Object object) {
    078        return object == this || decorated().equals(object);
    079    }
    080
    081    @Override
    082    public E get(final int index) {
    083        return decorated().get(index);
    084    }
    085
    086    @Override
    087    public int hashCode() {
    088        return decorated().hashCode();
    089    }
    090
    091    @Override
    092    public int indexOf(final Object object) {
    093        return decorated().indexOf(object);
    094    }
    095
    096    @Override
    097    public int lastIndexOf(final Object object) {
    098        return decorated().lastIndexOf(object);
    099    }
    100
    101    @Override
    102    public ListIterator<E> listIterator() {
    103        return decorated().listIterator();
    104    }
    105
    106    @Override
    107    public ListIterator<E> listIterator(final int index) {
    108        return decorated().listIterator(index);
    109    }
    110
    111    @Override
    112    public E remove(final int index) {
    113        return decorated().remove(index);
    114    }
    115
    116    @Override
    117    public E set(final int index, final E object) {
    118        return decorated().set(index, object);
    119    }
    120
    121    @Override
    122    public List<E> subList(final int fromIndex, final int toIndex) {
    123        return decorated().subList(fromIndex, toIndex);
    124    }
    125
    126}