    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.jexl3.internal.introspection;
    018
    019import java.lang.reflect.Array;
    020import java.util.AbstractList;
    021import java.util.RandomAccess;
    022
    023/**
    024 * A class that wraps an array within an AbstractList.
    025 * <p>
    026 * It overrides some methods because introspection uses this class a a marker for wrapped arrays; the declared class
    027 * for these method is thus ArrayListWrapper.
    028 * The methods are get/set/size/contains and indexOf because it is used by contains.
    029 * </p>
    030 */
    031public class ArrayListWrapper extends AbstractList<Object> implements RandomAccess {
    032    /** the array to wrap. */
    033    private final Object array;
    034
    035    /**
    036     * Create the wrapper.
    037     * @param anArray {@link #array}
    038     */
    039    public ArrayListWrapper(final Object anArray) {
    040        if (!anArray.getClass().isArray()) {
    041            throw new IllegalArgumentException(anArray.getClass() + " is not an array");
    042        }
    043        this.array = anArray;
    044    }
    045
    046    @Override
    047    public Object get(final int index) {
    048        return Array.get(array, index);
    049    }
    050
    051    @Override
    052    public Object set(final int index, final Object element) {
    053        final Object old = Array.get(array, index);
    054        Array.set(array, index, element);
    055        return old;
    056    }
    057
    058    @Override
    059    public int size() {
    060        return Array.getLength(array);
    061    }
    062
    063    @Override
    064    public int indexOf(final Object o) {
    065        final int size = size();
    066        if (o == null) {
    067            for (int i = 0; i < size; i++) {
    068                if (get(i) == null) {
    069                    return i;
    070                }
    071            }
    072        } else {
    073            for (int i = 0; i < size; i++) {
    074                if (o.equals(get(i))) {
    075                    return i;
    076                }
    077            }
    078        }
    079        return -1;
    080    }
    081
    082    @Override
    083    public boolean contains(final Object o) {
    084        return indexOf(o) != -1;
    085    }
    086}