[DBUTILS-97] Add an Abstract ResultSetHandler implementation in order to reduce redundant 'resultSet' variable invocation

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.6
• Fix Version/s: 1.6
• Assignee: Simone Tripodi
• Reporter: Simone Tripodi
• Created: 06/Aug/12 10:48
• Updated: 20/Jul/14 08:48
• Resolved: 21/Sep/12 14:02

Description

According to the DRY principle (Don't Repeat Yourself), repeating resultSet variable inside the ResultSetHandler#handle(ResultSet) over and over for each iteration can get a little tedious.
It would be helpful adding a support class, named AbstractResultSetHandler, which implicitly gives users access to ResultSet's methods. For example, we could extend AbstractResultSetHandler and rewrite the mapping below:

new ResultSetHandler<Collection<Map<String, Object>>> {

    @Override
    public Collection<Map<String, Object>> handle(ResultSet rs) throws SQLException {
        Collection<Map<String, Object>> result = new LinkedList<Map<String, Object>>();

        while (rs.next()) {
            Map<String, Object> current = new HashMap<String, Object>();
            for (int i = 1; i <= rs.getMetaData().getColumnCount(); i++) {
                current.put(rs.getMetaData().getColumnName(i), rs.getObject(i));
            }

            result.add(current);
        }

        return result;
    }

}

as:

new AbstractResultSetHandler<Collection<Map<String, Object>>> {

    @Override
    protected Collection<Map<String, Object>> handle() throws SQLException {
        Collection<Map<String, Object>> result = new LinkedList<Map<String, Object>>();

        while (next()) {
            Map<String, Object> current = new HashMap<String, Object>();
            for (int i = 1; i <= getMetaData().getColumnCount(); i++) {
                current.put(getMetaData().getColumnName(i), getObject(i));
            }

            result.add(current);
        }

        return result;
    }

}