Spring AMQP - 如果我在带有 @SendTo 注释的 Rabbit 侦听器方法中 return null 怎么办?

Spring AMQP - what if I return null in a Rabbit listener method with @SendTo annotation?

Spring AMQP 文档说:

Assuming our processOrder method should now return an OrderStatus, it is possible to write it as follow to automatically send a reply:

@RabbitListener(destination = "myQueue")
@SendTo("status")
public OrderStatus processOrder(Order order) {
    // order processing
    return status;
}

如果我 return 在 processOrder 方法末尾设置一个 null 会怎样?它会向 MQ 发送空对象还是什么都不做?

如果您return null,将不会发送回复。在 TRACE 级别日志记录下,您将看到一条日志消息 No result object given - no result to handle.