Named inner classes in methods

Do you know the feeling when you write something that should totally be wrong and it turns out perfectly ok? Well that's what I just experienced: A "WTF?! This is really cool" moment. What gives?

I've been entertaining myself with a little bit of Spring Data exercise. Trying to understand how much will I gain from using JdbcTemplate I dug a little into the sources of that class. At one point I saw that there's a named class (not an anonymous one) declared inside a method. WTF?

I know if I say it like that it is kind of lame of me not to know this. But this is such a nice feature I can't really understand why it's being used so rarely...

public String getName(String user) {
    JdbcTemplate template = new JdbcTemplate(this.datasource);

    class NameExtractor implements ResultSetExtractor {
        @Override
        public String extractData(ResultSet rs) 
            throws SQLException, DataAccessException {
            return rs.getString("firstName") + " " + rs.getString("lastName");
        }
    }

    return template.query("SELECT * FROM users WHERE id=1", new NameExtractor());
}

I know there's like a ton of different ways of writing that code but I have chosen this simple example to show you (and me in a couple of weeks maybe) that inner classes don't need to be defined on class levels.

Have fun!