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 example;
  
  import org.apache.activemq.ActiveMQConnectionFactory;
  import org.apache.activemq.command.ActiveMQTopic;
  
  import jakarta.jms.*;
  
  class Listener {
  
      public static void main(String []args) throws JMSException {
  
          String user = env("ACTIVEMQ_USER", "admin");
          String password = env("ACTIVEMQ_PASSWORD", "password");
          String host = env("ACTIVEMQ_HOST", "localhost");
          int port = Integer.parseInt(env("ACTIVEMQ_PORT", "61616"));
          String destination = arg(args, 0, "event");
  
          ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory("tcp://" + host + ":" + port);
  
          Connection connection = factory.createConnection(user, password);
          connection.start();
          Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
          Destination dest = new ActiveMQTopic(destination);
  
          MessageConsumer consumer = session.createConsumer(dest);
          long start = System.currentTimeMillis();
          long count = 1;
          System.out.println("Waiting for messages...");
          while(true) {
              Message msg = consumer.receive();
              if( msg instanceof  TextMessage ) {
                  String body = ((TextMessage) msg).getText();
                  if( "SHUTDOWN".equals(body)) {
                      long diff = System.currentTimeMillis() - start;
                      System.out.println(String.format("Received %d in %.2f seconds", count, (1.0*diff/1000.0)));
                      break;
                  } else {
                      if( count != msg.getIntProperty("id") ) {
                          System.out.println("mismatch: "+count+"!="+msg.getIntProperty("id"));
                      }
                      count = msg.getIntProperty("id");
  
                      if( count == 0 ) {
                          start = System.currentTimeMillis();
                      }
                      if( count % 1000 == 0 ) {
                          System.out.println(String.format("Received %d messages.", count));
                      }
                      count ++;
                  }
  
              } else {
                  System.out.println("Unexpected message type: "+msg.getClass());
              }
          }
          connection.close();
      }
  
      private static String env(String key, String defaultValue) {
          String rc = System.getenv(key);
          if( rc== null )
              return defaultValue;
          return rc;
      }
  
      private static String arg(String []args, int index, String defaultValue) {
          if( index < args.length )
              return args[index];
          else
              return defaultValue;
      }
  }