code: private void closeStatement(Statement stmt) {
      if (stmt != null) {
        try {
          stmt.close();
        } catch (SQLException e) {
          logger.error("Could not close JDBC Statement", e);
        } catch (Throwable e) {
          logger.error("Unexpected exception on closing JDBC Statement", e);
        }
      }
    }
docs: 关闭语句
  
  @param stmt