/*

  * 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.giraph.function;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * Allows multiple Consumers to be combined into a single Consumer, by having

  * them all subscribe to this object, and then using this object as a group

  * Consumer.

  *

  * @param <T> Argument type

  */

 public class ObjectNotifier<T> implements Consumer<T>, Notifier<T> {

   /** List of subscribers */

   private final List<Consumer<T>> subscribers = new ArrayList<>();

   @Override

   public void apply(T value) {

     for (Consumer<T> consumer : subscribers) {

       consumer.apply(value);

     }

   }

   @Override

   public void subscribe(Consumer<T> consumer) {

     subscribers.add(consumer);

   }

   @Override

   public String toString() {

     return getClass() + " [subscribers=" + subscribers + "]";

   }

 }