问如何从任务中调用Java / Scala函数？

EN

val labelAndPreds = testData.map { point =>
  val prediction = model.predict(point.features)
  (point.label, prediction)
}

labelsAndPredictions = testData.map(
    lambda lp: (lp.label, model.predict(lp.features))
labelsAndPredictions.first()

predictions = model.predict(testData.map(lambda x: x.features))
labelsAndPredictions = testData.map(lambda lp: lp.label).zip(predictions)

/**
 * Predict values for a single data point using the model trained.
 *
 * @param features array representing a single data point
 * @return Double prediction from the trained model
 */
def predict(features: Vector): Double = {
  topNode.predict(features)
}

/**
 * Predict values for the given data set using the model trained.
 *
 * @param features RDD representing data points to be predicted
 * @return RDD of predictions for each of the given data points
 */
def predict(features: RDD[Vector]): RDD[Double] = {
  features.map(x => predict(x))
}