private List executeQueryOneColumn()

in backend/src/main/java/org/apache/iotdb/admin/service/impl/IotDBServiceImpl.java [4534:4580]
47 lines of code
10 McCabe index (conditional complexity)

  private List<String> executeQueryOneColumn(SessionPool sessionPool, String sql)
      throws BaseException {
    SessionDataSetWrapper sessionDataSetWrapper = null;
    ExecutorService service = null;
    try {
      Callable call = () -> sessionPool.executeQueryStatement(sql);
      service = Executors.newFixedThreadPool(1);
      Future submit = service.submit(call);
      sessionDataSetWrapper = (SessionDataSetWrapper) submit.get(60, TimeUnit.SECONDS);
      int batchSize = sessionDataSetWrapper.getBatchSize();
      List<String> values = new ArrayList<>();
      if (batchSize > 0) {
        while (sessionDataSetWrapper.hasNext()) {
          RowRecord rowRecord = sessionDataSetWrapper.next();
          List<org.apache.iotdb.tsfile.read.common.Field> fields = rowRecord.getFields();
          values.add(fields.get(0).toString());
        }
      }
      return values;
    } catch (IoTDBConnectionException e) {
      logger.error(e.getMessage());
      throw new BaseException(ErrorCode.GET_SESSION_FAIL, ErrorCode.GET_SESSION_FAIL_MSG);
    } catch (StatementExecutionException e) {
      logger.error(e.getMessage());
      if (e.getStatusCode() == 602) {
        throw new BaseException(ErrorCode.NO_PRI_DO_THIS, ErrorCode.NO_PRI_DO_THIS_MSG);
      } else {
        throw new BaseException(
            ErrorCode.GET_SQL_ONE_COLUMN_FAIL, ErrorCode.GET_SQL_ONE_COLUMN_FAIL_MSG);
      }
    } catch (InterruptedException e) {
      e.printStackTrace();
      throw new BaseException(ErrorCode.TIME_OUT, ErrorCode.TIME_OUT_MSG);
    } catch (ExecutionException e) {
      e.printStackTrace();
      if (e.getMessage().contains("600")) {
        throw new BaseException(ErrorCode.WRONG_USER, ErrorCode.WRONG_USER_MSG);
      }
      throw new BaseException(ErrorCode.CONN_REFUSED, ErrorCode.CONN_REFUSED_MSG);
    } catch (TimeoutException e) {
      logger.error(e.getMessage());
      throw new BaseException(ErrorCode.TIME_OUT, ErrorCode.TIME_OUT_MSG);
    } finally {
      service.shutdown();
      closeResultSet(sessionDataSetWrapper);
    }
  }