    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;
    018
    019    import java.io.Serializable;
    020
    021    import org.apache.commons.lang3.builder.HashCodeBuilder;
    022
    023    /**
    024     * A basic immutable Object pair.
    025     *
    026     * <p>#ThreadSafe# if the objects are threadsafe</p>
    027     * @since Lang 3.0
    028     * @author Matt Benson
    029     * @version $Id: Pair.java 967237 2010-07-23 20:08:57Z mbenson $
    030     */
    031    public final class Pair<L, R> implements Serializable {
    032        /** Serialization version */
    033        private static final long serialVersionUID = 4954918890077093841L;
    034
    035        /** Left object */
    036        public final L left;
    037
    038        /** Right object */
    039        public final R right;
    040
    041        /**
    042         * Create a new Pair instance.
    043         * @param left
    044         * @param right
    045         */
    046        public Pair(L left, R right) {
    047            this.left = left;
    048            this.right = right;
    049        }
    050
    051        /**
    052         * {@inheritDoc}
    053         */
    054        @Override
    055        public boolean equals(Object obj) {
    056            if (obj == this) {
    057                return true;
    058            }
    059            if (obj instanceof Pair<?, ?> == false) {
    060                return false;
    061            }
    062            Pair<?, ?> other = (Pair<?, ?>) obj;
    063            return ObjectUtils.equals(left, other.left) && ObjectUtils.equals(right, other.right);
    064        }
    065
    066        /**
    067         * {@inheritDoc}
    068         */
    069        @Override
    070        public int hashCode() {
    071            return new HashCodeBuilder().append(left).append(right).toHashCode();
    072        }
    073
    074        /**
    075         * Returns a String representation of the Pair in the form: (L,R)
    076         */
    077        @Override
    078        public String toString() {
    079            StringBuilder builder = new StringBuilder();
    080            builder.append("(");
    081            builder.append(left);
    082            builder.append(",");
    083            builder.append(right);
    084            builder.append(")");
    085            return builder.toString();
    086        }
    087
    088        /**
    089         * Static creation method for a Pair<L, R>.
    090         * @param <L>
    091         * @param <R>
    092         * @param left
    093         * @param right
    094         * @return Pair<L, R>(left, right)
    095         */
    096        public static <L, R> Pair<L, R> of(L left, R right) {
    097            return new Pair<L, R>(left, right);
    098        }
    099    }