Package fr.mines_stetienne.ci.sparql_generate.ws

Class ITER_WebSocket

java.lang.Object
fr.mines_stetienne.ci.sparql_generate.iterator.IteratorStreamFunctionBase
fr.mines_stetienne.ci.sparql_generate.ws.ITER_WebSocket
All Implemented Interfaces:
fr.mines_stetienne.ci.sparql_generate.iterator.IteratorFunction
public class ITER_WebSocket extends fr.mines_stetienne.ci.sparql_generate.iterator.IteratorStreamFunctionBase
Iterator function iter:WebSocket connects to a WebSocket server, and iteratively binds the messages that are received.

See Live example

Optionally, a specific message can be sent to the WebSocket server as a first step (This message is usually a query that specifies what stream of data is to be retrieved).
  • Param 1: (a String or URI) is the WebSocket server URI to connect to;
  • Param 3: (a String, optional) is the message that will be first sent to the server (e.g., a json query).

Example:

The clause

ITERATOR iter:WebSocket("wss://api.gemini.com/v1/marketdata/BTCUSD") AS ?events

will connect to the Gemini WebSocket server (a cryptocurrency exchange platform) forever and iteratively produce the following bindings:

 ?events => {"type":"update","eventId":4568099292,"timestamp":1537974017,"timestampms":1537974017597,"socket_sequence":1,"events":[{"type":"change","side":"ask","price":"6513.20","remaining":"0","delta":"-1.321","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099362,"timestamp":1537974018,"timestampms":1537974018434,"socket_sequence":2,"events":[{"type":"change","side":"bid","price":"1.00","remaining":"5666.001","delta":"0.001","reason":"place"}]}
 ?events => {"type":"update","eventId":4568099456,"timestamp":1537974019,"timestampms":1537974019735,"socket_sequence":3,"events":[{"type":"change","side":"bid","price":"6504.97","remaining":"0","delta":"-1","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099464,"timestamp":1537974019,"timestampms":1537974019919,"socket_sequence":4,"events":[{"type":"change","side":"ask","price":"6513.20","remaining":"0.104","delta":"0.104","reason":"place"}]}
 ?events => {"type":"update","eventId":4568099470,"timestamp":1537974020,"timestampms":1537974020197,"socket_sequence":5,"events":[{"type":"trade","tid":4568099470,"price":"6508.45","amount":"0.02441407","makerSide":"ask"},{"type":"change","side":"ask","price":"6508.45","remaining":"0.45117186","delta":"-0.02441407","reason":"trade"}]}
 ?events => {"type":"update","eventId":4568099488,"timestamp":1537974020,"timestampms":1537974020414,"socket_sequence":6,"events":[{"type":"change","side":"bid","price":"6492.03","remaining":"0","delta":"-0.2","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099494,"timestamp":1537974020,"timestampms":1537974020515,"socket_sequence":7,"events":[{"type":"change","side":"ask","price":"6544.36","remaining":"0","delta":"-0.2","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099498,"timestamp":1537974020,"timestampms":1537974020542,"socket_sequence":8,"events":[{"type":"change","side":"ask","price":"6513.20","remaining":"0","delta":"-0.104","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099513,"timestamp":1537974020,"timestampms":1537974020623,"socket_sequence":9,"events":[{"type":"change","side":"bid","price":"6491.40","remaining":"0.2","delta":"0.2","reason":"place"}]}
 ?events => {"type":"update","eventId":4568099529,"timestamp":1537974020,"timestampms":1537974020723,"socket_sequence":10,"events":[{"type":"change","side":"ask","price":"6543.79","remaining":"0.2","delta":"0.2","reason":"place"}]}
 ?events => {"type":"update","eventId":4568099531,"timestamp":1537974020,"timestampms":1537974020726,"socket_sequence":11,"events":[{"type":"change","side":"bid","price":"1.00","remaining":"5666","delta":"-0.001","reason":"cancel"}]}
 ?events => {"type":"update","eventId":4568099631,"timestamp":1537974021,"timestampms":1537974021785,"socket_sequence":12,"events":[{"type":"change","side":"bid","price":"6504.37","remaining":"1","delta":"1","reason":"place"}]}
Since:
2018-09-26

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static String
    URI
    The SPARQL function URI.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ITER_WebSocket()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    checkBuild​(org.apache.jena.sparql.expr.ExprList args)
     
    void
    exec​(List<org.apache.jena.sparql.expr.NodeValue> args, Consumer<List<List<org.apache.jena.sparql.expr.NodeValue>>> listListNodeValue)
     

    Methods inherited from class fr.mines_stetienne.ci.sparql_generate.iterator.IteratorStreamFunctionBase

    build, exec, getContext

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • ITER_WebSocket

      public ITER_WebSocket()

  • Method Details

    • checkBuild

      public void checkBuild​(org.apache.jena.sparql.expr.ExprList args)
      Specified by:
      checkBuild in class fr.mines_stetienne.ci.sparql_generate.iterator.IteratorStreamFunctionBase

    • exec

      public void exec​(List<org.apache.jena.sparql.expr.NodeValue> args, Consumer<List<List<org.apache.jena.sparql.expr.NodeValue>>> listListNodeValue)
      Specified by:
      exec in class fr.mines_stetienne.ci.sparql_generate.iterator.IteratorStreamFunctionBase