XChange-stream

NOTE: This project is in the process of being merged into the XChange library. Large, sweeping changes are in progress. Consider asking first if working on a large pull request, since it is likely to suffer considerably conflicts if mis-timed.

XChange-stream is a Java library providing a simple and consistent streaming API for interacting with Bitcoin and other crypto currency exchanges via WebSocket protocol.

It is build on top of the XChange library providing new interfaces for the exchanges' streaming APIs. Users can subscribe for live updates via reactive streams of RxJava library.

Why use it?

Easy to use - no need to hack WebSocket and other backends.
Consistent & simple API across all implemented exchanges.
Extends well-known & active Java library XChange.
Reactive streams are fun to work with.
Modular extensibility.

Getting started

Include in your project

Xchange-stream is on Maven Central. You will need xchange-stream-core dependency and xchange-XYZ where XYZ is supported exchange (eg. xchange-bitstamp). Add the following into your pom.xml.

Maven

<dependency>
    <groupId>info.bitrich.xchange-stream</groupId>
    <artifactId>xchange-stream-core</artifactId>
    <version>x.y.z</version>
</dependency>

<dependency>
    <groupId>info.bitrich.xchange-stream</groupId>
    <artifactId>xchange-XYZ</artifactId>
    <version>x.y.z</version>
</dependency>

For snapshots version (built from develop branch), add the following repository to your pom.xml file.

<repository>
  <id>sonatype-oss-snapshot</id>
  <snapshots/>
  <url>https://oss.sonatype.org/content/repositories/snapshots</url>
</repository>

Versioning

XChange-stream follows major and minor version from XChange library. So version 4.2.x is based on latest 4.2. release of XChange.

Example

Use the same library as XChange but instead of ExchangeFactory use StreamingExchangeFactory that creates StreamingExchange instead of Exchange. Then you can call getStreamingMarketDataService to subscribe to trade data.

StreamingExchange exchange = StreamingExchangeFactory.INSTANCE.createExchange(BitstampStreamingExchange.class.getName());

// Connect to the Exchange WebSocket API. Blocking wait for the connection.
exchange.connect().blockingAwait();

// Subscribe to live trades update.
exchange.getStreamingMarketDataService()
        .getTrades(CurrencyPair.BTC_USD)
        .subscribe(trade -> {
            LOG.info("Incoming trade: {}", trade);
        }, throwable -> {
            LOG.error("Error in subscribing trades.", throwable);
        });

// Subscribe order book data with the reference to the subscription.
Disposable subscription = exchange.getStreamingMarketDataService()
                                  .getOrderBook(CurrencyPair.BTC_USD)
                                  .subscribe(orderBook -> {
                                       // Do something
                                  });

// Unsubscribe from data order book.
subscription.dispose();

// Disconnect from exchange (non-blocking)
exchange.disconnect().subscribe(() -> LOG.info("Disconnected from the Exchange"));

More information about reactive streams can be found at RxJava wiki.

What is supported

Listening for live updates of:

Exchange	order books	trades (public)	tickers	balances	trades (user)	open orders	notes
Bankera	✔️	✔️	🚧	❓	❓	❓	Ticker support could be implemented using the trades and order book streams, even though the exchange doesn't explicitly return a ticker stream.
Binance	✔️	✔️	✔️	✔️	✔️	✔️
Bitfinex	✔️	✔️	✔️	✔️	✔️	✔️
Bitflyer	✔️	✔️	✔️	❓	❓	❓
BitMEX	✔️	✔️	✔️	🚧	🚧	🚧	We are short of maintainers able to review pull requests and provide support for Bitmex, so there is a backlog of pull requests and support is likely broken. Can you help? See #180 for reference if attempting to add private channel support.
Bitstamp	✔️	✔️	❌	❓	❓	❓
CEX.IO	✔️	❌	❌	❓	❓	❓	New support, not widely tested
Coinbase Pro	✔️	✔️	✔️	✔️	✔️	✔️
Coinmate	✔️	✔️	❌	✔️	✔️	✔️
Gemini	✔️	✔️	❌	🚧	🚧	🚧
Kraken	✔️	✔️	✔️	❌	✔️	✔️
LGO	✔️	✔️	✔️	✔️	✔️	✔️
OKCoin	✔️	✔️	✔️	❓	❓	❓
OKEx	✔️	✔️	✔️	❓	❓	❓	See #180 for reference if attempting to add private channel support.
Poloniex	✔️	✔️	✔️	❓	❓	❓

✔️ - implemented
🚧 - missing but can be implemented
❌ - not supported by the exchange
❓ - exchange support level not known (please fill in)

If you missing a specific exchange implementation, feel free to propose a pull request or open an issue with some sweet BTC bounty.

Open Source Projects Using XChange-Stream

This is an, not so complete, list of projects that use XChange-Stream, feel free to add your project below.

XChange-Trade-Bot by yurivin
Crypto Websockets by firepol
CryptoRealTime by galic1987
Orko - Multi-exchange trading by gruelbox/badgerwithagun

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

mladenmarkov/xchange-stream