Treasure Hill Artist Village, Taiwan, 2019/03/31

HiveMQ 4 Notes

What’s new:

• Supports MQTT 5
• Shared Subscriptions
• Requires JDK11

Differences between MQTT 3 and 5

• Supports JWT (via the AUTH packet)
• Supports disconnect reason
  > DISCONNECT packets can carry Reason Codes, so it’s easy to indicate what was the reason for the disconnection (e.g. in case of invalid permissions)
• New Data Type: UTF-8 String pairs

mqtt/mqtt.github.io

MQTT 5: Is it time to upgrade to MQTT 5 yet?

MQTT 5 Features & Hidden Gems: Introduction to MQTT 5

P̶l̶u̶g̶i̶n̶ Extension

Replaced hivemq-spi with hivemq-extension-sdk

hivemq/hivemq-extension-sdk

I found hivemq-extension-sdk requires JDK9, it doesn’t make sense, because it doesn’t use anything JDK9 specific, so I recompiled it for JDK8:

yongjhih/hivemq-extension-sdk

dependencies {
    implementation 'com.github.yongjhih:hivemq-extension-sdk:65af6066b1'
}

And then I made a hivemq-hello-work-extension project which supports gradle build:

yongjhih/hivemq-hello-world-extension

Misc

• Released hivemq-mqtt-client for java which supports RxJava (No Android Optimization yet)
• Official docker images on docker hub: https://hub.docker.com/r/hivemq/hivemq4
• I found they implemented with Null-safety and misc annotations

HiveMQ MQTT Client

Usage:

It doesn’t support auto-reconnect yet (it will soon), we can do a simple backoff:

References

Hivemq 4 Whats New

HiveMQ 4 Early Access Preview

Introduction :: HiveMQ Documentation