App.java

/**
 * The MIT License
 * Copyright (c) 2014-2016 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.iluwatar.event.aggregator;

import java.util.ArrayList;
import java.util.List;

/**
 * 
 * A system with lots of objects can lead to complexities when a client wants to subscribe to
 * events. The client has to find and register for each object individually, if each object has
 * multiple events then each event requires a separate subscription.
 * <p>
 * An Event Aggregator acts as a single source of events for many objects. It registers for all the
 * events of the many objects allowing clients to register with just the aggregator.
 * <p>
 * In the example {@link LordBaelish}, {@link LordVarys} and {@link Scout} deliver events to
 * {@link KingsHand}. {@link KingsHand}, the event aggregator, then delivers the events to
 * {@link KingJoffrey}.
 *
 */
public class App {

  /**
   * Program entry point
   * 
   * @param args command line args
   */
  public static void main(String[] args) {

    KingJoffrey kingJoffrey = new KingJoffrey();
    KingsHand kingsHand = new KingsHand(kingJoffrey);

    List<EventEmitter> emitters = new ArrayList<>();
    emitters.add(kingsHand);
    emitters.add(new LordBaelish(kingsHand));
    emitters.add(new LordVarys(kingsHand));
    emitters.add(new Scout(kingsHand));

    for (Weekday day : Weekday.values()) {
      for (EventEmitter emitter : emitters) {
        emitter.timePasses(day);
      }
    }
  }
}