1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.giraph.function; 19 20 import java.util.ArrayList; 21 import java.util.List; 22 23 /** 24 * Allows multiple Consumers to be combined into a single Consumer, by having 25 * them all subscribe to this object, and then using this object as a group 26 * Consumer. 27 * 28 * @param <T> Argument type 29 */ 30 public class ObjectNotifier<T> implements Consumer<T>, Notifier<T> { 31 /** List of subscribers */ 32 private final List<Consumer<T>> subscribers = new ArrayList<>(); 33 34 @Override 35 public void apply(T value) { 36 for (Consumer<T> consumer : subscribers) { 37 consumer.apply(value); 38 } 39 } 40 41 @Override 42 public void subscribe(Consumer<T> consumer) { 43 subscribers.add(consumer); 44 } 45 46 @Override 47 public String toString() { 48 return getClass() + " [subscribers=" + subscribers + "]"; 49 } 50 }