    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     */
    017    package 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 Lang 3.0
    028     * @version $Id: MutablePair.java 1127544 2011-05-25 14:35:42Z scolebourne $
    029     */
    030    public class MutablePair<L, R> extends Pair<L, R> {
    031
    032        /** Serialization version */
    033        private static final long serialVersionUID = 4954918890077093841L;
    034
    035        /** Left object */
    036        public L left;
    037        /** Right object */
    038        public R right;
    039
    040        /**
    041         * <p>Obtains an immutable pair of from two objects inferring the generic types.</p>
    042         *
    043         * <p>This factory allows the pair to be created using inference to
    044         * obtain the generic types.</p>
    045         *
    046         * @param <L> the left element type
    047         * @param <R> the right element type
    048         * @param left  the left element, may be null
    049         * @param right  the right element, may be null
    050         * @return a pair formed from the two parameters, not null
    051         */
    052        public static <L, R> MutablePair<L, R> of(L left, R right) {
    053            return new MutablePair<L, R>(left, right);
    054        }
    055
    056        /**
    057         * Create a new pair instance of two nulls.
    058         */
    059        public MutablePair() {
    060            super();
    061        }
    062
    063        /**
    064         * Create a new pair instance.
    065         *
    066         * @param left  the left value, may be null
    067         * @param right  the right value, may be null
    068         */
    069        public MutablePair(L left, R right) {
    070            super();
    071            this.left = left;
    072            this.right = right;
    073        }
    074
    075        //-----------------------------------------------------------------------
    076        /**
    077         * {@inheritDoc}
    078         */
    079        @Override
    080        public L getLeft() {
    081            return left;
    082        }
    083
    084        /**
    085         * Sets the left element of the pair.
    086         *
    087         * @param left  the new value of the left element, may be null
    088         */
    089        public void setLeft(L left) {
    090            this.left = left;
    091        }
    092
    093        /**
    094         * {@inheritDoc}
    095         */
    096        @Override
    097        public R getRight() {
    098            return right;
    099        }
    100
    101        /**
    102         * Sets the right element of the pair.
    103         *
    104         * @param right  the new value of the right element, may be null
    105         */
    106        public void setRight(R right) {
    107            this.right = right;
    108        }
    109
    110        /**
    111         * Sets the {@code Map.Entry} value.
    112         * This sets the right element of the pair.
    113         *
    114         * @param value  the right value to set, not null
    115         * @return the old value for the right element
    116         */
    117        public R setValue(R value) {
    118            R result = getRight();
    119            setRight(value);
    120            return result;
    121        }
    122
    123    }