| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.functor.aggregator.functions; |
| |
| import java.util.List; |
| |
| import org.apache.commons.functor.Function; |
| |
| /** |
| * Aggregator function to be used with subclasses of |
| * {@link org.apache.commons.functor.aggregator.AbstractListBackedAggregator} |
| * which finds the maximum number in a list. It does this by traversing the list |
| * (once) -- so the complexity of this will be <i>O(n)</i>. |
| */ |
| public class IntegerMaxAggregatorFunction implements Function<List<Integer>, Integer> { |
| /** |
| * Does the actual traversal of the list and finds the maximum value then |
| * returns the result. Please note that caller is responsible for |
| * synchronizing access to the list. |
| * |
| * @param data |
| * List to traverse and find max |
| * @return max number in the list or null if the list is empty. |
| */ |
| public Integer evaluate(List<Integer> data) { |
| if (data == null || data.size() == 0) { |
| return null; |
| } |
| Integer max = null; |
| for (Integer d : data) { |
| if (max == null) { |
| max = d; |
| } else { |
| if (max.intValue() < d.intValue()) { |
| max = d; |
| } |
| } |
| } |
| return max; |
| } |
| |
| @Override |
| public String toString() { |
| return IntegerMaxAggregatorFunction.class.getName(); |
| } |
| } |