A Retrofit inspired WebSocket client for Kotlin, Java, and Android.
We are working on a new version of Scarlet that supports other persistent connection protocols: ServerSentEvent, Socket IO, STOMP, and MQTT. It can be found on the 0.2.x
branch and is available at com.github.tinder:scarlet:0.2.1-alpha4
.
In this example, we read the realtime Bitcoin price from Gdax WebSocket Feed. For more information, please check out the demo app.
Declare a WebSocket client using an interface:
interface GdaxService {
@Receive
fun observeWebSocketEvent(): Flowable<WebSocket.Event>
@Send
fun sendSubscribe(subscribe: Subscribe)
@Receive
fun observeTicker(): Flowable<Ticker>
}
Use Scarlet to create an implementation:
val scarletInstance = Scarlet.Builder()
.webSocketFactory(okHttpClient.newWebSocketFactory("wss://ws-feed.gdax.com"))
.addMessageAdapterFactory(MoshiMessageAdapter.Factory())
.addStreamAdapterFactory(RxJava2StreamAdapter.Factory())
.build()
val gdaxService = scarletInstance.create<GdaxService>()
Send a Subscribe
message upon connection open and the server will start streaming tickers which contain the latest price.
val BITCOIN_TICKER_SUBSCRIBE_MESSAGE = Subscribe(
productIds = listOf("BTC-USD"),
channels = listOf("ticker")
)
gdaxService.observeWebSocketEvent()
.filter { it is WebSocket.Event.OnConnectionOpened<*> }
.subscribe({
gdaxService.sendSubscribe(BITCOIN_TICKER_SUBSCRIBE_MESSAGE)
})
gdaxService.observeTicker()
.subscribe({ ticker ->
Log.d("Bitcoin price is ${ticker.price} at ${ticker.time}")
})
Scarlet is driven by a StateMachine.
TODO
While we are working on Bintray support, Scarlet is available via JitPack.
<repository>
<id>jitpack.io</id>
<url>https://jitpack.io</url>
</repository>
<dependency>
<groupId>com.github.tinder.scarlet</groupId>
<artifactId>scarlet</artifactId>
<version>latestVersion</version>
</dependency>
repositories {
// ...
maven { url "https://jitpack.io" }
}
implementation 'com.github.tinder.scarlet:scarlet:$latestVersion'
WebSocket.Factory
-
OkHttpClient
-
MockHttpServer
MessageAdapter.Factory
-
moshi
-
gson
-
protobuf
-
jackson
-
simple-xml
StreamAdapter.Factory
-
RxJava2
-
RxJava1
-
Kotlin Coroutine
Lifecycle
-
AndroidLifecycle
BackoffStrategy
-
Linear
-
Exponential
-
ExponentialWithJitter
Copyright (c) 2018, Match Group, LLC
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
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without specific prior written permission.
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