Multiple candlestick events on single websocket connection

[alicanalbayrak]

Binance provides to access multiple symbols at single websocket connection by combining stream names.

Combined streams are accessed at /stream?streams<streamName1>/<streamName2>/<streamName3>

Here, I added trivial method to listen candlestick events on multiple symbols.

[mcourteaux]

Have you actually tested this? Because the documentation states that you need to use

• Combined streams are accessed at /stream?streams=<streamName1>/<streamName2>/<streamName3>

Whereas you seem to be using this:

public static final String WS_API_BASE_URL = "wss://stream.binance.com:9443/ws";

The documentation also states that the combined streams are wrapped:

Combined stream events are wrapped as follows: {"stream":"<streamName>","data":<rawPayload>}

You also don't seem to do any unwrapping. I'd be surprised if your proposed changes would work, given that they are so non-conform the documentation.

[mcourteaux]

• Unwrapping not done.
• Wrong API WSS endpoint.

[alicanalbayrak]

I'm suprised too, I have tested and its working. You are right, I wasn't aware that I'm using this "wss://stream.binance.com:9443/ws"; endpoint.

[alicanalbayrak]

@mcourteaux I have added methods to consume (aggregated trade, depth and candlestick events ) from "wss://stream.binance.com:9443/stream?streams="

[mcourteaux]

I'll review your changes soon. We also implemented working combined streams. I'll compare your changes to ours. Still working on something else now.

[joaopsilva]

Hi @alicanalbayrak , thanks for your contribution, could you please resolve the conflicts?

[alicanalbayrak]

Hi @joaopsilva , sorry for the late reply. I resolved conflicting files. Can you please review?

[joaopsilva]

Thank you @alicanalbayrak , this is looking good, I'll need to test a bit further, and I'll most likely merge it afterwards.

[hsinhunglee]

Hi, it looks doesn't work. I find the bug at
main.java.com.binance.api.client.impl/BinanceApiWebSocketClientImpl.java
correct:
String streamingUrl = String.format("%s%s", streamUrl, channel);
wrong:
String streamingUrl = String.format("%s/%s", streamUrl, channel);
I corrected it, then it work!

[Gilianp]

As mensioned by @hsinhunglee, when remove "/" from format the problem is fixed :)

[joaopsilva]

Fixed in #178.