Rcaller file returning as empty

Question

I am relative new to R and am attempting to call R from my Java code. I was using rJava but faced errors and so switched to rCaller. However, while executing a sample test code the output is coming as empty file. Can anyone shed some light on this? Help will be much appreciated!

Note: Try_prediction.r is a Rscript I wrote. When I am doing var <- try_prediction() in RStudio the required results are coming.

It is similar to this problem faced here.

My Code:

import rcaller.RCaller;
import rcaller.RCode;
import rcaller.exception.ExecutionException;

public class Second_R {
    public static void main (String args[]){
    try {
        RCaller rcall = new RCaller();
        rcall.setRscriptExecutable("D:/Program Files/R/R-3.2.0/bin/x64/Rscript.exe");
        RCode code = new RCode ();
        code.clear();
        code.R_source("D:/650444/RScript/matchData.R");
        code.R_source("D:/650444/RScript/try_prediction.R");
        code.addRCode("library('forecast')");
        code.addRCode("var <- try_prediction()");
        rcall.setRCode(code);
        rcall.runAndReturnResult("var");
        try {
            System.out.println(rcall.getParser().getXMLFileAsString());
            //String[] result = rcall.getParser().getAsStringArray("var");
            //for(int i=0;i<result.length;i++)
            //System.out.println(result[i]);
            } catch (Exception e) {
                System.out.println("Error in accessing XML");
            }
    } catch (ExecutionException e) {
        e.printStackTrace();
    }
  }
}

My Output:

 <?xml version="1.0"?><root></root>