Java / Android Websocket无法连接到Spark Websocket服务，但JavaScript可以

Question

I want to connect to an open Spark websocket server. For me, this server is located at ws://192.168.56.1:4567/chat/. When I try connecting to it using JavaScript running on the computer, it works:

var websocket = new WebSocket("ws://192.168.56.1:4567/chat/");

This code successfully connects to the websocket. On Android using java-websocket, this snippet looks like this:

val client = Client(URI("ws://192.168.56.1:4567/chat/"))

I use Kotlin, the equivalent Java Code is

Client client = new Client(new URI("ws://192.168.56.1:4567/chat/"));

where Client is a class extending WebSocketClient. When I try to connect to the websocket, it simply does not work and times out as if this websocket didn't exist at all. I do have INTERNET enabled in my manifest file:

<uses-permission android:name="android.permission.INTERNET" />
<application
[...]

and I tried to ping Google and that worked, so I really don't know what causes this. Thank you for any help!

Answer 1

So for some reason you have to use Draft_17 like this:

val client = Client(URI("ws://192.168.56.1:4567/chat/"), Draft_17())

This is not well documented.