code: public static List<Map<String, Object>> getListMap(String sql, Object... arg) {
          Connection connection = JDBCUtils.getConnection();
          PreparedStatement ps = null;
          ResultSet result = null;
          List<Map<String, Object>> listMap = new ArrayList<Map<String, Object>>();
          try {
              ps = connection.prepareStatement(sql);
              for (int i = 0; i < arg.length; i++) {
                  ps.setObject(i + 1, arg[i]);
              }
  
              result = ps.executeQuery();
              listMap = DBUtils.handleResultSetToMapList(result, listMap);
          } catch (SQLException e) {
              e.printStackTrace();
          } finally {
              JDBCUtils.release(result, ps, connection);
          }
          return listMap;
      }
docs: 把查询结果里的每条记录包装成一个map对象，并将所有map对象放入传入的数组中
  
  @param sql 传入的SQL 语句
  @param arg 占位符参数
  @return 返回一个包含所有记录的map对象的的集合数组，若没有记录，则返回一个空数组