    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 *      https://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.lang3.tuple;
    018
    019import java.util.Objects;
    020
    021/**
    022 * A mutable triple consisting of three {@link Object} elements.
    023 *
    024 * <p>Not #ThreadSafe#</p>
    025 *
    026 * @param <L> the left element type.
    027 * @param <M> the middle element type.
    028 * @param <R> the right element type.
    029 * @since 3.2
    030 */
    031public class MutableTriple<L, M, R> extends Triple<L, M, R> {
    032
    033    /**
    034     * The empty array singleton.
    035     * <p>
    036     * Consider using {@link #emptyArray()} to avoid generics warnings.
    037     * </p>
    038     *
    039     * @since 3.10
    040     */
    041    public static final MutableTriple<?, ?, ?>[] EMPTY_ARRAY = {};
    042
    043    /** Serialization version */
    044    private static final long serialVersionUID = 1L;
    045
    046    /**
    047     * Returns the empty array singleton that can be assigned without compiler warning.
    048     *
    049     * @param <L> the left element type.
    050     * @param <M> the middle element type.
    051     * @param <R> the right element type.
    052     * @return the empty array singleton that can be assigned without compiler warning.
    053     * @since 3.10
    054     */
    055    @SuppressWarnings("unchecked")
    056    public static <L, M, R> MutableTriple<L, M, R>[] emptyArray() {
    057        return (MutableTriple<L, M, R>[]) EMPTY_ARRAY;
    058    }
    059
    060    /**
    061     * Obtains a mutable triple of three objects inferring the generic types.
    062     *
    063     * @param <L> the left element type.
    064     * @param <M> the middle element type.
    065     * @param <R> the right element type.
    066     * @param left  the left element, may be null.
    067     * @param middle  the middle element, may be null.
    068     * @param right  the right element, may be null.
    069     * @return a mutable triple formed from the three parameters, not null.
    070     */
    071    public static <L, M, R> MutableTriple<L, M, R> of(final L left, final M middle, final R right) {
    072        return new MutableTriple<>(left, middle, right);
    073    }
    074
    075    /**
    076     * Obtains a mutable triple of three non-null objects inferring the generic types.
    077     *
    078     * @param <L> the left element type.
    079     * @param <M> the middle element type.
    080     * @param <R> the right element type.
    081     * @param left  the left element, may not be null.
    082     * @param middle  the middle element, may not be null.
    083     * @param right  the right element, may not be null.
    084     * @return a mutable triple formed from the three parameters, not null.
    085     * @throws NullPointerException if any input is null.
    086     * @since 3.13.0
    087     */
    088    public static <L, M, R> MutableTriple<L, M, R> ofNonNull(final L left, final M middle, final R right) {
    089        return of(Objects.requireNonNull(left, "left"), Objects.requireNonNull(middle, "middle"), Objects.requireNonNull(right, "right"));
    090    }
    091
    092    /** Left object. */
    093    public L left;
    094    /** Middle object. */
    095    public M middle;
    096
    097    /** Right object. */
    098    public R right;
    099
    100    /**
    101     * Create a new triple instance of three nulls.
    102     */
    103    public MutableTriple() {
    104    }
    105
    106    /**
    107     * Create a new triple instance.
    108     *
    109     * @param left  the left value, may be null.
    110     * @param middle  the middle value, may be null.
    111     * @param right  the right value, may be null.
    112     */
    113    public MutableTriple(final L left, final M middle, final R right) {
    114        this.left = left;
    115        this.middle = middle;
    116        this.right = right;
    117    }
    118
    119    /**
    120     * {@inheritDoc}
    121     */
    122    @Override
    123    public L getLeft() {
    124        return left;
    125    }
    126
    127    /**
    128     * {@inheritDoc}
    129     */
    130    @Override
    131    public M getMiddle() {
    132        return middle;
    133    }
    134
    135    /**
    136     * {@inheritDoc}
    137     */
    138    @Override
    139    public R getRight() {
    140        return right;
    141    }
    142
    143    /**
    144     * Sets the left element of the triple.
    145     *
    146     * @param left  the new value of the left element, may be null.
    147     */
    148    public void setLeft(final L left) {
    149        this.left = left;
    150    }
    151
    152    /**
    153     * Sets the middle element of the triple.
    154     *
    155     * @param middle  the new value of the middle element, may be null.
    156     */
    157    public void setMiddle(final M middle) {
    158        this.middle = middle;
    159    }
    160
    161    /**
    162     * Sets the right element of the triple.
    163     *
    164     * @param right  the new value of the right element, may be null.
    165     */
    166    public void setRight(final R right) {
    167        this.right = right;
    168    }
    169}
    170