public ResponseEntity<byte []> getInfo(
      @PathVariable("id") String distributorId, @PathVariable("country")
      String country) throws JSONException, IOException,
      URISyntaxException, ParseException, DocumentException {
      logger.trace(START);
      ByteArrayOutputStream myDetails =
      enrollmentService.getInfo(id,country);
      HttpHeaders headers = new HttpHeaders();
      headers.setContentType(MediaType.parseMediaType("application/pdf"));
      String filename = "output.pdf";
      headers.setContentDispositionFormData(filename, filename);
      headers.setCacheControl("must-revalidate, post-check=0, pre-check=0");
      byte[] sos=myDetails.toByteArray();
      return new ResponseEntity<>(sos,headers, sos == null ?
      HttpStatus.NO_CONTENT : HttpStatus.OK );
      }

getInfo(distributorId: string,
  country:string,month:number,year:number): Observable<any> {
  let url='Some sample url';

  return this._http.
   get(url, { responseType: ResponseContentType.ArrayBuffer })
   .map((response: Response) => response.arrayBuffer())
   .map((arrayBuffer: ArrayBuffer) => new Uint8Array(arrayBuffer))
  .catch(this.handleErrorObservable);
 }

RangeError: byte length of Uint16Array should be a multiple of 2
at new Uint16Array (native)