    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.lang3.tuple;
    018
    019/**
    020 * <p>A mutable pair consisting of two {@code Object} elements.</p>
    021 *
    022 * <p>Not #ThreadSafe#</p>
    023 *
    024 * @param <L> the left element type
    025 * @param <R> the right element type
    026 *
    027 * @since 3.0
    028 */
    029public class MutablePair<L, R> extends Pair<L, R> {
    030
    031    /** Serialization version */
    032    private static final long serialVersionUID = 4954918890077093841L;
    033
    034    /** Left object */
    035    public L left;
    036    /** Right object */
    037    public R right;
    038
    039    /**
    040     * <p>Obtains a mutable pair of two objects inferring the generic types.</p>
    041     *
    042     * <p>This factory allows the pair to be created using inference to
    043     * obtain the generic types.</p>
    044     *
    045     * @param <L> the left element type
    046     * @param <R> the right element type
    047     * @param left  the left element, may be null
    048     * @param right  the right element, may be null
    049     * @return a pair formed from the two parameters, not null
    050     */
    051    public static <L, R> MutablePair<L, R> of(final L left, final R right) {
    052        return new MutablePair<>(left, right);
    053    }
    054
    055    /**
    056     * Create a new pair instance of two nulls.
    057     */
    058    public MutablePair() {
    059        super();
    060    }
    061
    062    /**
    063     * Create a new pair instance.
    064     *
    065     * @param left  the left value, may be null
    066     * @param right  the right value, may be null
    067     */
    068    public MutablePair(final L left, final R right) {
    069        super();
    070        this.left = left;
    071        this.right = right;
    072    }
    073
    074    //-----------------------------------------------------------------------
    075    /**
    076     * {@inheritDoc}
    077     */
    078    @Override
    079    public L getLeft() {
    080        return left;
    081    }
    082
    083    /**
    084     * Sets the left element of the pair.
    085     *
    086     * @param left  the new value of the left element, may be null
    087     */
    088    public void setLeft(final L left) {
    089        this.left = left;
    090    }
    091
    092    /**
    093     * {@inheritDoc}
    094     */
    095    @Override
    096    public R getRight() {
    097        return right;
    098    }
    099
    100    /**
    101     * Sets the right element of the pair.
    102     *
    103     * @param right  the new value of the right element, may be null
    104     */
    105    public void setRight(final R right) {
    106        this.right = right;
    107    }
    108
    109    /**
    110     * Sets the {@code Map.Entry} value.
    111     * This sets the right element of the pair.
    112     *
    113     * @param value  the right value to set, not null
    114     * @return the old value for the right element
    115     */
    116    @Override
    117    public R setValue(final R value) {
    118        final R result = getRight();
    119        setRight(value);
    120        return result;
    121    }
    122
    123}