Question

我写了一个简单的python程序来连接RabbitMqtt服务器，希望生成一个队列并发布消息。但是，在构建连接并创建队列之后，消息未成功发布（当我检查消息的信息时，我找不到任何记录和数据）。我想知道我错过了client.publish()中的一些参数或设置，但我不知道如何解决这个问题。

import paho.mqtt.client as mqtt


# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    print("Connected with result code " + str(rc))

    # Subscribing in on_connect() means that if we lose the connection and
    # reconnect then subscriptions will be renewed.
    client.subscribe('SEEDQ')
    client.publish('SEEDQ', 'deqwdqwefqwefwefqwefqwe', 0, False)

# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
    print(msg.topic + " " + str(msg.payload))


client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message

client.connect("15.78.xx.xx", 1883, 60)

client.loop_forever()

Answer 1

问题是您在连接完成之前调用client.publish（）。将client.publish移动到on_connect函数，在client.subscribe（＆＃39; SEEDQ＆＃39;）之后，它将起作用。

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    print("Connected with result code "+str(rc))

    # Subscribing in on_connect() means that if we lose the connection and
    # reconnect then subscriptions will be renewed.
#    client.subscribe("$SYS/#")
    client.subscribe('SEEDQ')
    client.publish('SEEDQ', 111, 0, False)

输出：

Connected with result code 0
SEEDQ 111

仅供参考我在iot.eclipse.org，端口1883使用了公共测试服务器。

仅供参考，有一个非常有用的浏览器客户端HERE - 使用此公共测试服务器messagesight.demos.ibm.com端口1883您可以订阅SEEDQ并查看您的python脚本发布，并使用浏览器客户端可以从浏览器发布到SEEDQ，并且脚本将在loop_forever（）中显示消息。显然，使用这些测试服务器是公开可见的。

UPDATE这里是完整的代码 - 这对我上面显示的公共服务器起作用。

import paho.mqtt.client as mqtt

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    print("Connected with result code "+str(rc))

    # Subscribing in on_connect() means that if we lose the connection and
    # reconnect then subscriptions will be renewed.
#    client.subscribe("$SYS/#")
    client.subscribe('SEEDQ')
    client.publish('SEEDQ', 111, 0, False)


# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
    print(msg.topic+" "+str(msg.payload))

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message

#client.connect('15.xx.xx.xx', 1883, 60)
#client.connect("iot.eclipse.org", 1883, 60)
client.connect("messagesight.demos.ibm.com", 1883, 60)

#client.publish('SEEDQ', 111, 0, False)

# Blocking call that processes network traffic, dispatches callbacks and
# handles reconnecting.
# Other loop*() functions are available that give a threaded interface and a
# manual interface.
client.loop_forever()

通过Mqtt将数据发布到RabbitMQ服务器

1 个答案: