Is it possible to convert the result of the createNativeQuery method from List to Map?

At the moment I have a method that returns an expense report. Earlier, when I used JDBC, there were problems with returning a report in the form of Map <String (category name), Long (amount of expenses for this category)> did not occur:

public Map<String, Long> expenseReport(long customerId, LocalDate startDate, LocalDate endDate) {
        Map<String, Long> map = new HashMap<>();
        try (Connection con = ds.getConnection()) {
            PreparedStatement ps = con.prepareStatement("SELECT c.category_name, sum(amount)\n" +
                    "FROM account as a\n" +
                    "left join transaction as t on account_from_id = account_id\n" +
                    "left join transaction_to_transaction_type tttt on t.transaction_id = tttt.transaction_id\n" +
                    "left join category c on tttt.transaction_type_id = c.category_id\n" +
                    "WHERE (t.data_created BETWEEN ? AND ?) AND a.customer_id = ? AND category_name notnull\n" +
                    "group by c.category_name;");
            ps.setObject(1, startDate);
            ps.setObject(2, endDate);
            ps.setLong(3, customerId);
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {
                map.put(rs.getString("category_name"), rs.getLong("amount"));
            }
        } catch (SQLException e) {
            throw new CustomException(e);
        }
        return map;
    }

Now, using JPA, I have a problem with returning the Map:

public List expenseReport(long customerId, LocalDate startDate, LocalDate endDate) {
        return em.createNativeQuery("select c.category_name, sum(amount)\n" +
                "from account as a\n" + "left join transaction as t on account_from_id = account_id\n" +
                "left join transaction_to_category ttc on t.transaction_id = ttc.transaction_id\n" +
                "left join category c on ttc.category_id = c.category_id\n" +
                "WHERE (t.data_created BETWEEN ? AND ?) AND a.customer_id = ? AND category_name notnull\n" + "group by c.category_name;").setParameter(1, customerId).setParameter(2, startDate).setParameter(3, endDate).getResultList();
    }

How can this problem be solved?

Try this

public Map<String, Long> expenseReport(long customerId, LocalDate startDate, LocalDate endDate) {
        List<Object[]> rows = em.createNativeQuery("select c.category_name, sum(amount)\n" +
                "from account as a\n" + "left join transaction as t on account_from_id = account_id\n" +
                "left join transaction_to_category ttc on t.transaction_id = ttc.transaction_id\n" +
                "left join category c on ttc.category_id = c.category_id\n" +
                "WHERE (t.data_created BETWEEN ? AND ?) AND a.customer_id = ? AND category_name notnull\n" + "group by c.category_name;").setParameter(1, customerId).setParameter(2, startDate).setParameter(3, endDate).getResultList();

    Map<String, Long> retVal = new HashMap<>();

    for (Object[] row : rows) {
        retVal.put(row[0], row[1]);
    }
    return retVal;
}