mqtt_packet_t *connect_packet = mqtt_connect("test_client", NULL, NULL); mqtt_send(socket_fd, connect_packet); printf("Sent MQTT CONNECT packet!\n"); free(connect_packet->data); free(connect_packet); // 接收 MQTT CONNACK 报文 mqtt_packet_t *connack_packet = (mqtt_packet_t *)...
Now, we will introduce the control packet used when disconnecting: DISCONNECT. In MQTT, both the client and the server can send a DISCONNECT packet to the other party before disconnecting the network connection, indicating the reason for the connection closure. The DISCONNECT packet sent by the ...
The CONNACK packet has no Payload. Conclusion CONNECT is the first MQTT packet sent by the client after the network connection between the client and the server is established. CONNACK, as the response packet of CONNECT, indicates the connection result through the reason code. The client and ser...
mqtt_packet_t *connect_packet = mqtt_connect("test_client", NULL, NULL); mqtt_send(socket_fd, connect_packet); printf("Sent MQTT CONNECT packet!n"); free(connect_packet->data); free(connect_packet); // 接收 MQTT CONNACK 报文 mqtt_packet_t *connack_packet = (mqtt_packet_t *)malloc...
m:publish("/topic","hello",0,0, function(client) print("sent") end) m:close(); -- 你可以再次调用 m:connect 连接函数 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.
在MQTT 中,客户端和服务端可以在断开网络连接前向对端发送一个 DISCONNECT 报文,来指示连接关闭的原因。客户端发送的 DISCONNECT 报文还可以影响服务端在连接断开后的行为,例如是否发送遗嘱消息,是否更新会话过期间隔。
6)打开EMQ的管理员控制台,可以看到一些相关的统计数据已经发生了变化。比如在“The messages data”表格中,“qos0/received”的值为1,说明EMQ收到了1条QoS0的消息;“qos0/sent”的值为1,表示EMQ转发了一条QoS0的消息。 好了,EMQ君带领着大家初步领略了MQTT服务器能够提供的基本功能,如果读者想了解其它MQTT服务...
OnAuthPacket 当接收到认证数据包时调用。它旨在允许开发人员创建自己的 MQTT v5 认证数据包处理机制。在这里允许数据包的修改。 OnPacketRead 当从客户端接收到数据包时调用。允许对数据包进行修改。 OnPacketEncode 在数据包被编码并发送给客户端之前立即调用。允许修改数据包。 OnPacketSent 在数据包已发送给客户端...
maximumPacketSize: representing the Maximum Packet Size the Client is willing to acceptnumber, topicAliasMaximum: representing the Topic Alias Maximum value indicates the highest value that the Client will accept as a Topic Alias sent by the Servernumber, ...
lastSent 是MQTT消息包发送完成,调用的场景如下2个: MQTTAsync_writeComplete MQTTPacket_send 一个完整的MQTT数据包发送完成,lastSent被设置为当前时间 发送的场景: 2.1. MQTTPacket_send_disconnect(...) 2.2. MQTTPacket_send_puback(...) // 调用的是 MQTTPacket_send_ack(...) ...