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.functor.aggregator.functions;
018
019import org.apache.commons.functor.BinaryFunction;
020
021/**
022 * Aggregator function to be used with subclasses of
023 * {@link org.apache.commons.functor.aggregator.AbstractNoStoreAggregator} which
024 * sums up the 2 given numbers (hence the "Binary" in the name!). Counterpart of
025 * {@link IntegerSumAggregatorFunction}.
026 */
027public final class IntegerSumAggregatorBinaryFunction implements BinaryFunction<Integer, Integer, Integer> {
028    /**
029     * Adds the 2 numbers together and returns the result.
030     *
031     * @param left
032     *            first number to add. If <code>null</code>, then
033     *            <code>right</code> will be returned.
034     * @param right
035     *            second number to add. If <code>null</code>, then
036     *            <code>left</code> will be returned.
037     * @return sum of the 2 int's as described above
038     */
039    public Integer evaluate(Integer left, Integer right) {
040        if (left == null) {
041            return right;
042        }
043        if (right == null) {
044            return left;
045        }
046        return left + right;
047    }
048
049    @Override
050    public String toString() {
051        return IntegerSumAggregatorBinaryFunction.class.getName();
052    }
053}