"mqtts://'' appended at my host

[lucanicoletti]

Expected behavior

When I use Mqtt3Client.builder() and set host & port with .serverHost(config.host).serverPort(config.port), a mqtts:// is appended, giving me a UnknownHostException when trying to connect.

Actual behavior

Do not modify the provided host+port

To Reproduce

Simply build a Mqtt3Client (async) with port and host, and try to connect, a "mqtts://" is appended at the host

Steps

Reproducer code

val client = Mqtt3Client.builder().serverHost(/** your host */).serverPort(/** your port */).buildAsync()
client.connect().whenComplete { mqtt3ConnAck, ex ->
    continuation.resume(!mqtt3ConnAck.returnCode.isError)
}

Details

• Affected HiveMQ MQTT Client version(s): 3
• Used JVM version: JVM 11 - embedded in Android Studio
• Used OS (name and version): MacOS Monterey 12.5.1 - using Android Studio
• Used MQTT version: com.hivemq:hivemq-mqtt-client:1.3.0
• Used MQTT broker (name and version): session broker v3

[SgtSilvio]

Hi @lucanicoletti the hivemq-mqtt-client does not add anything to the provided host. Where do you see the "mqtts://" prefix?

[lucanicoletti]

when I connect, I get the exception, with UnknownHostException: mqtts://{my host}. I figured out it's the protocol, and that I can set the protocols with .protocols(listOf()) providing a list of protocols, but the one I need fires a com.hivemq.client.mqtt.exceptions.ConnectionFailedException: java.lang.IllegalArgumentException: protocol ws is not supported

[SgtSilvio]

What do you pass to .serverHost(config.host)? I suspect config.host already contains mqtts://. The client library does not alter the provided hostname. There is not even an occurrence of "mqtts" in the code as you can see here: https://github.com/hivemq/hivemq-mqtt-client/search?q=mqtts

I figured out it's the protocol, and that I can set the protocols with .protocols(listOf()) providing a list of protocols

I guess you are referring to https://github.com/hivemq/hivemq-mqtt-client/blob/master/src/main/java/com/hivemq/client/mqtt/MqttClientSslConfigBuilderBase.java#L78. This is only to set the TLS protocol(s), for example "TLSv1.2" or "TLSv1.3".

Can you provide more details

• if you are using TLS?
• if you are using WebSockets?

[lucanicoletti]

Closing as it was completely my mistake! We received 2 values (one with mqtt pre-appended) and one without, a mapper deepdown our architecture was mapping the wrong one into the value (config.host) we were using. Thanks for the support.