[PAID GIG] Help Implement XChange Library Into B4J App

cklester

Well-Known Member
Licensed User
About March of this year (or thereabouts), I paid several hundred dollars to Saif and his crew as downpayment on a project. Unfortunately, that has never been delivered. Now that they are down and out, it seems it might never be completed, and I might be out a lot of money.

I'm reaching out to the community again to see if I can get someone to help develop an app incorporating the XChange library.

We would only need to develop it to work with one exchange--say, Binance, Kraken, or Coinbase--and it should then be applicable to all the exchanges. The library facilitates the same interface to all the exchange libraries, so once done, it is all done.

Please reach out if you can help with this.
 

cklester

Well-Known Member
Licensed User
mcqueccu said:
They have APIs which can be easily integrated.
Click to expand...

The nice thing with the XChange library is that all the APIs are already programmed and use a common interface. Program your app once, and all exchanges are available.

Otherwise, each exchange does its thing differently, and you'd have to customize your B4J codefor each exchange...

mcqueccu said:
Which platform are you targeting?
Click to expand...

B4J
 
P

pipocas

Member
Hello.
Just for fun, had a look at it, since the subject interests me also. But the damn thing is huge. It will take months to do properly.
I was able to wrap a couple of the methods from the classes needed for the first example, "Get Bitcoin Ticker Data from Bitstamp" . Just look at the #AdditionalJars needed to make it run. But it does run, i get
B4X: 
Ticker [instrument=BTC/USD, open=62014.99, last=64133.02, bid=64138.13, ask=64150.69, high=64367.14, low=61350.00,avg=63069.30, volume=3192.44872716, quoteVolume=null, timestamp=1634685275000, bidSize=null, askSize=null, percentageChange=null]

B4X: 
#Region Project Attributes
    #MainFormWidth: 600
    #MainFormHeight: 600
    #AdditionalJar: slf4j-simple-1.7.32
    #AdditionalJar: slf4j-api-1.7.32
    #AdditionalJar: rescu-2.0.2
    #AdditionalJar: signpost-core-1.2.1.2.jar
    #AdditionalJar: jsr305-3.0.2.jar
    #AdditionalJar: javax.ws.rs-api-2.1.jar
    #AdditionalJar: jackson-databind-2.9.1.jar
    #AdditionalJar: jackson-core-2.9.1.jar
    #AdditionalJar: jackson-annotations-2.9.0.jar
    #AdditionalJar: commons-codec-1.3.jar
    #AdditionalJar: guava-30.1.1-jre.jar
    #AdditionalJar: resilience4j-all-1.7.0
    #AdditionalJar: resilience4j-retry-1.7.0
    #AdditionalJar: resilience4j-ratelimiter-1.7.0
    #AdditionalJar: resilience4j-core-1.7.0.jar
    #AdditionalJar: resilience4j-circuitbreaker-1.7.0.jar
    #AdditionalJar: resilience4j-cache-1.7.0.jar
    #AdditionalJar: resilience4j-bulkhead-1.7.0.jar
    #AdditionalJar: vavr-match-0.10.2.jar
    #AdditionalJar: vavr-0.10.2.jar
#End Region

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Private xui As XUI
    Private Button1 As B4XView
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("Layout1")
    MainForm.Show
    
    Dim bitStampExchange As xChange
    Dim bitstamp As BitStamp
    
    
    bitStampExchange.Initialize(bitstamp.name)
    Dim dataService As  MarketDataService
    
    dataService = bitStampExchange.MarketDataService
    Log(dataService.Ticker)
    
End Sub
 

cklester

Well-Known Member
Licensed User
pipocas said:
Just for fun, had a look at it, since the subject interests me also. But the damn thing is huge. It will take months to do properly.
Click to expand...

You only have to complete the code for one exchange to have them all... supposedly. All exchanges use the same unified interface. We need to make the app somehow non-exchange-centric.

pipocas said:
I was able to wrap a couple of the methods from the classes needed for the first example, "Get Bitcoin Ticker Data from Bitstamp"
Click to expand...

That's a great start! ?

Are you able to get the websocket/ticker data as well?

So, how did you do it? Did you create a B4X library?
 
P

pipocas

Member
Hi. Yes, it's a b4j library.
Will play with it later tonight, since i have no idea what websocket/ticker data is.
But this will be "jar hell". Keeping all the jars updated will be a pain.

In the mean time, i'm looking at https://github.com/ccxt/ccxt , looks way better in terms of keeping the app updated.
 

behnam_tr

Active Member
Licensed User
Longtime User
can you upload wrapped java source ??
i need for learning ...
thanks
 
P

pipocas

Member
I can now write this b4j code (not sure about the results, but looks good)
B4X: 
Dim x As xChange
    Dim exchangeList As List
    Dim spec As ExchangeSpecification 'Ignore
    
    exchangeList.Initialize
    exchangeList.Add( x.Initialize(spec.EXCHANGE_BitStamp ))
    exchangeList.Add( x.Initialize(spec.EXCHANGE_Poloinex ))
    exchangeList.Add( x.Initialize(spec.EXCHANGE_Yobit ))
    
    For Each exchange As xChange In exchangeList
        Dim dataService As  MarketDataService
        Dim exchangeSpec As ExchangeSpecification
        
        dataService = exchange.MarketDataService
        exchangeSpec = exchange.ExchangeSpecification
        Log("Exchange : " &  exchangeSpec.ExchangeDescription)
        Dim tick As Ticker
        For Each coinPair As String In Array As String("BTC-USD", "ETH-USD", "LTC-EUR")
            Try
                tick=dataService.getTicker(coinPair)
    
                Log(tick.Ask)
                Log(tick.AskSize)
                Log(tick.Bid)
                Log(tick.BidSize)
                Log(tick.CurrencyPair)
                Log(tick.hashCode)
                Log(tick.High)
                Log(tick.Last)
                Log(tick.Low)
                Log(tick.Open)
                Log(tick.PercentageChange)
                Log(tick.QuoteVolume)
                Log(tick.Timestamp)
                Log(tick.Volume)
                Log(tick.Vwap)
                Log(tick.toString)
            Catch
                Log("Error : " & LastException.Message )       
            End Try
        Next
    Next
 
P

pipocas

Member
@ behnam_tr : Partial code done for one of the classes.

Java: 
    @ShortName("ExchangeSpecification")
    public static class Exchangespecification extends AbsObjectWrapper<ExchangeSpecification> {
        
        public final String EXCHANGE_BitStamp = "org.knowm.xchange.bitstamp.BitstampExchange";
        public final String EXCHANGE_Poloinex = "org.knowm.xchange.poloniex.PoloniexExchange";
        public final String EXCHANGE_Yobit = "org.knowm.xchange.yobit.YoBitExchange";
        public final String EXCHANGE_OkCoin = "org.knowm.xchange.okcoin.OkCoinExchange";
        
        
        public Exchangespecification initialize(String exchangeClassName) {
            setObject( new ExchangeSpecification(exchangeClassName) );
            return this;
        }
        public String getApiKey() {
            return getObject().getApiKey();
        }
        public Exchangespecification setApiKey(String apiKey) {
            getObject().setApiKey(apiKey);
            return this;
        }
        public String getExchangeDescription() {
            return getObject().getExchangeDescription();
        }   
        public String getExchangeName() {
            return getObject().getExchangeName();
        }
        public anywheresoftware.b4a.objects.collections.Map getExchangeSpecificParameters() {
            anywheresoftware.b4a.objects.collections.Map m = new anywheresoftware.b4a.objects.collections.Map();
            
            m.Initialize();
            m.getObject().putAll(this.getObject().getExchangeSpecificParameters());
            return m;
        }
    }
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…