SGMController.java

@RestController
public class SGMController {
  
  private ModelEvaluator<MiningModel> modelEvaluator;

  @PostConstruct
  public void init() {
    try {
      PMML pmml = createPMMLfromFile("iris_rf.pmml");
      modelEvaluator = new MiningModelEvaluator(pmml);
    } catch (SAXException | JAXBException | IOException e) {
      e.printStackTrace();
    }
  }

  @RequestMapping(value = "/ping", method = RequestMethod.GET)
  public String ping() {
    return "";
  }


  @RequestMapping(value = "/invocations", method = RequestMethod.POST)
  public String invoke(HttpServletRequest request) throws IOException {
    return predict(request.getReader().lines(), modelEvaluator);
  }


  private static String predict(Stream<String> inputData,
      ModelEvaluator<MiningModel> modelEvaluator) {
    
    String returns = inputData.map(dataLine -> {
      Map<FieldName, FieldValue> arguments = readArgumentsFromLine(dataLine, modelEvaluator);
      modelEvaluator.verify();
      Map<FieldName, ?> results = modelEvaluator.evaluate(arguments);
      FieldName targetName = modelEvaluator.getTargetField();
      Object targetValue = results.get(targetName);
      ProbabilityClassificationMap nodeMap = (ProbabilityClassificationMap) targetValue;

      return  ( nodeMap != null && nodeMap.getResult() !=  null) ? nodeMap.getResult().toString() : "NA for input->"+dataLine;
    }).collect(Collectors.joining(System.lineSeparator()));

    return returns;

  }


  private static PMML createPMMLfromFile(String fileName)
      throws SAXException, JAXBException, IOException {

    try (
      InputStream pmmlFile = SGMController.class.getClassLoader().getResourceAsStream(fileName)) {
      String pmmlString = new Scanner(pmmlFile).useDelimiter("\\Z").next();
      InputStream is = new ByteArrayInputStream(pmmlString.getBytes());
      InputSource source = new InputSource(is);
      SAXSource transformedSource = ImportFilter.apply(source);
      return JAXBUtil.unmarshalPMML(transformedSource);
    }
  }


  private static Map<FieldName, FieldValue> readArgumentsFromLine(String line,
      ModelEvaluator<MiningModel> modelEvaluator) {
    Map<FieldName, FieldValue> arguments = new LinkedHashMap<FieldName, FieldValue>();
    String[] lineArgs = line.split(",");

    if (lineArgs.length != 5)
      return arguments;

    FieldValue sepalLength = modelEvaluator.prepare(new FieldName("Sepal.Length"),
        lineArgs[0].isEmpty() ? 0 : lineArgs[0]);
    FieldValue sepalWidth = modelEvaluator.prepare(new FieldName("Sepal.Width"),
        lineArgs[1].isEmpty() ? 0 : lineArgs[1]);
    FieldValue petalLength = modelEvaluator.prepare(new FieldName("Petal.Length"),
        lineArgs[2].isEmpty() ? 0 : lineArgs[2]);
    FieldValue petalWidth = modelEvaluator.prepare(new FieldName("Petal.Width"),
        lineArgs[3].isEmpty() ? 0 : lineArgs[3]);

    arguments.put(new FieldName("Sepal.Length"), sepalLength);
    arguments.put(new FieldName("Sepal.Width"), sepalWidth);
    arguments.put(new FieldName("Petal.Length"), petalLength);
    arguments.put(new FieldName("Petal.Width"), petalWidth);

    return arguments;
  }
}