RabbitMQ Java Client針對既有的Queue取得Message Count

ConnectionFactory factory = new ConnectionFactory();
factory.setHost(HOST);
factory.setVirtualHost(VIRTUAL_HOST);
factory.setUsername(USER_NAME);
factory.setPassword(PASSWORD);
factory.setPort(PORT);

Connection conn = factory.newConnection();
Channel channel = conn.createChannel();

/*
* get message count of queue
*/
int messageCount = channel.queueDeclarePassive(QUEUE_NAME).getMessageCount();
System.out.println(messageCount);