Custom C# like event in JAVA?

Question

I have a simple Java web client that connects to a WSDL service on HTTP Binding running on localhost. I have written a method in the WSDL service that returns a double variable to the client. And I will use that variable in my further classes. I am using ScheduledExceutorService thread for periodically scanning the price from the WSDL service at a rate of 10ms.

Sometimes I get the data from the service and some times I don't get. This is not an issue and it happens like that. All I want is, this needs be event based now. That is, only when I get the data from the WSDL service then only I have to catch that. My executor thread continuously scans the wsdl service. How can I eliminate this by writing an event based program. I have seen the below link , but I am a little bit confused with my situation.

creating Event in Java

This is my code:

import com.microsoft.schemas._2003._10.serialization.arrays.ArrayOfstring;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

public class GetLTPData implements Runnable{

public static ArrayOfstring al=new ArrayOfstring();
public static List<String> list = new ArrayList<String>();
String symbol ="GC";
String exg = "NDF";
String expiry = "201706";
String security = "FUT";

  public static double getLTPdata(String symbol,String exchange,String expiry,String securitytp) throws InterruptedException {
     try{
      al  = javaItem(symbol,exchange,expiry,securitytp);
     }
     catch( Exception e ){
     }
      list = al.getString();

      if(list.size()== 0)
       throw new InterruptedException();
      else 
          return Double.parseDouble(list.get(0));

  }
   @Override
  public void run() {
      try{
      getLTPdata(symbol,exg,expiry,security);
      }
      catch(InterruptedException ie){
          System.err.println(ie.getMessage());
      }
  }

//Below is the C# service I am calling private static ArrayOfstring javaItem(java.lang.String symbol, java.lang.String exchange, java.lang.String expiryDate, java.lang.String securityType) {

        org.tempuri.JavaBroadCastEx service = new org.tempuri.JavaBroadCastEx();
        org.tempuri.IJavaBroadCast port = service.getBasicHttpBindingIJavaBroadCast();
        return port.javaItem(symbol, exchange, expiryDate, securityType);
    }
   public static void main(String[] args){
    GetLTPData data = new GetLTPData();
     ScheduledExecutorService executor1 = Executors.newScheduledThreadPool(2);
            // Create Repetitive task for every 100ms
    ScheduledFuture<?> result = executor1.scheduleAtFixedRate(data, 10, 10, TimeUnit.MILLISECONDS);

    }
}