使用 Java 向 IoT 中心发送 C2D 消息

Question

Is there any possibility to send Cloud2Device message to an IoT Hub with Java by using MQTT as protocol?

I use ServiceClient from library: https://github.com/Azure/azure-iot-sdk-java/blob/main/service/iot-service-client/src/main/java/com/microsoft/azure/sdk/iot/service/ServiceClient.java and there it's impossible using MQTT, only AMQPS.

Answer 1

You can receive Cloud2Device messages on your device, using the Device SDK , if you are connected over MQTT, AMQP or HTTPS.

In order to connect to your IoTHub from your solution back end, using the Service SDK to send cloud-to-device messages to a single device you will need to use AMQP or AMQP over Websockets.

Service endpoints. Each IoT hub exposes a set of endpoints for your solution back end to communicate with your devices. With one exception, these endpoints are only exposed using the AMQP and AMQP over WebSockets protocols.

Ref: Reference - IoT Hub endpoints