private boolean filterNullValueAndMeasurementWithStringType(
      List<String> valuesList, String deviceId, List<String> measurementsList) {
    Map<String, Object> nullMap = new HashMap<>();
    for (int i = valuesList.size() - 1; i >= 0; i--) {
      if (valuesList.get(i) == null) {
        nullMap.put(measurementsList.get(i), valuesList.get(i));
        valuesList.remove(i);
        measurementsList.remove(i);
      }
    }
    if (valuesList.isEmpty()) {
      logger.info("All values of the {} are null,null values are {}", deviceId, nullMap);
      return true;
    } else {
      logger.info("Some values of {} are null,null values are {}", deviceId, nullMap);
    }
    return false;
  }
When the value is null,filter this,don't use this measurement.

@return true:all value is null;false:not all null value is null.
iotdb-client/session/src/main/java/org/apache/iotdb/session/Session.java