content: /**
   * 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.activemq.advisory;
  
  import java.util.EventObject;
  
  import jakarta.jms.Destination;
  
  import org.apache.activemq.command.ConsumerId;
  
  /**
   * An event when the number of consumers on a given destination changes.
   * 
   * 
   */
  public abstract class ConsumerEvent extends EventObject {
      private static final long serialVersionUID = 2442156576867593780L;
      private final Destination destination;
      private final ConsumerId consumerId;
      private final int consumerCount;
  
      public ConsumerEvent(ConsumerEventSource source, Destination destination, ConsumerId consumerId, int consumerCount) {
          super(source);
          this.destination = destination;
          this.consumerId = consumerId;
          this.consumerCount = consumerCount;
      }
  
      public ConsumerEventSource getAdvisor() {
          return (ConsumerEventSource) getSource();
      }
  
      public Destination getDestination() {
          return destination;
      }
  
      /**
       * Returns the current number of consumers active at the time this advisory was sent.
       * 
       * Note that this is not the number of consumers active when the consumer started consuming.
       * It is usually more vital to know how many consumers there are now - rather than historically
       * how many there were when a consumer started. So if you create a {@link ConsumerListener}
       * after many consumers have started, you will receive a ConsumerEvent for each consumer. However the
       * {@link #getConsumerCount()} method will always return the current active consumer count on each event.
       */
      public int getConsumerCount() {
          return consumerCount;
      }
  
      public ConsumerId getConsumerId() {
          return consumerId;
      }
  
      public abstract boolean isStarted();
  }
  