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订阅Java后端中的AWS IoT主题

[英]Subscribing to an AWS IoT topic in a Java backend

原文 2018-08-24 06:19:01 2 1 java/ amazon-web-services/ aws-sdk/ aws-iot

When using the AWS Java SDK ( aws-java-sdk-iot ) it is possible to publish messages to an AWS IoT topic from a backend system, but it doesn't seem possible to subscribe to a topic? 使用AWS Java SDK （ aws-java-sdk-iot ）时，可以从后端系统将消息发布到AWS IoT主题，但似乎无法订阅该主题？ What is the reasoning behind this? 这背后的原因是什么？

We are looking for a way to have our Java backend (deployed on AWS) take part in our IoT solution and being able to publish and subscribe to topics. 我们正在寻找一种方法来让我们的Java后端（在AWS上部署）参与我们的IoT解决方案，并能够发布和订阅主题。 If using the sdk is not the way to go, what would be a good design to achieve this? 如果没有使用sdk的方法，那么实现此目的的最佳设计是什么？

We do not want to use the AWS Device SDK for this. 我们不想为此使用AWS Device SDK。

1 个解决方案

The non-device SDKs for IoT are request/response oriented and use the HTTP protocol. 物联网的非设备SDK面向请求/响应，并使用HTTP协议。 It would be a weird API (see the SQS API) if it held open an HTTP request until a message arrived on a subscription. 如果它一直打开HTTP请求，直到消息到达订阅，这将是一个怪异的API（请参阅SQS API）。

The AWS Device SDK is not a bad choice, but you could avoid using it by doing the same thing it does and set up a persistent connection to the broker using MQTT or MQTT + WebSocket. AWS Device SDK并不是一个不错的选择，但是您可以通过做相同的事情来避免使用它，并使用MQTT或MQTT + WebSocket设置与代理的持久连接。

If you decide to roll your own MQTT client, using Netty and its MQTT codec would be a reasonable place to start. 如果您决定推出自己的MQTT客户端，那么使用Netty及其MQTT编解码器将是一个不错的起点。