How to get data from Postgres DB as Java Map?

public List<Map<String, Object>> readResultSetAsList(String query) throws SQLException {
    System.out.println("query(" + query + ")");
    Statement queryStatement = connection.createStatement();
    ResultSet resultSet = queryStatement.executeQuery(query);
    ResultSetMetaData md = resultSet.getMetaData();
    int columns = md.getColumnCount();
    List<Map<String, Object>> rows = new ArrayList<Map<String, Object>>();
    while (resultSet.next()) {
      Map<String, Object> row = new HashMap<String, Object>(columns);
      for (int i = 1; i <= columns; ++i) {
        row.put(md.getColumnName(i), resultSet.getObject(i));
      }
      rows.add(row);
    }
    System.out.println("rows=====" + rows);
    return rows;
  }

public Map<String, List<Object>> readResultSet(String query) {
    System.out.println("query(" + query + ")");
    Map<String, List<Object>> resultList = null;
    try {
      Statement queryStatement = connection.createStatement();
      ResultSet resultSet = queryStatement.executeQuery(query);
      ResultSetMetaData md = resultSet.getMetaData();
      int columnCount = resultSet.getMetaData().getColumnCount();

      resultList = new HashMap<>(columnCount);
      for (int i = 1; i <= columnCount; ++i) {
        resultList.put(md.getColumnName(i), new ArrayList<>());
      }
      while (resultSet.next()) {
        for (int i = 1; i <= columnCount; ++i) {
          resultList.get(md.getColumnName(i)).add(resultSet.getObject(i));
        }
      }
      System.out.println("resultList=====" + resultList);

      resultSet.close();
      queryStatement.close();
    } catch (SQLException e) {
      Assert.fail(
          "Failed to execute query("
              + query
              + ")! Reason - "
              + e.getSQLState()
              + " "
              + e.getMessage());
    }
    return resultList;
  }