ConfirmListener为何没有消息确认的时候，也会触发handleAck方法的执行

[weixin_38113341]

public class Test { public static void main( String[] args ) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("127.0.0.1"); factory.setPort(5672); factory.setUsername("guest"); factory.setPassword("guest"); factory.setVirtualHost("/"); Connection conn = factory.newConnection(); Channel channel = conn.createChannel(); channel.confirmSelect(); channel.addConfirmListener(new ConfirmListener() { public void handleAck(long deliveryTag, boolean multiple) throws IOException { System.out.println("=============handleAck============"); System.out.println("deliveryTag : " + deliveryTag); } public void handleNack(long deliveryTag, boolean multiple) throws IOException { System.out.println("=============handleNack============"); System.out.println("deliveryTag : " + deliveryTag); } }); BasicProperties props = new BasicProperties.Builder().deliveryMode(2).contentEncoding("UTF-8").build(); channel.basicPublish("", "test.queue", props, "test".getBytes()); TimeUnit.SECONDS.sleep(10); channel.close(); conn.close(); } } 这段代码，是往test.queue上发送一个消息。当前test.queue上没有任何消费者。 但是为啥执行这段代码，就会触发handleAck方法的执行呢？  又没有消费者去确认消息，怎么会触发handleAck方法的执行呢？  求答疑。 RabbitMQ版本为3.6.10