It's impossible to pass by reference int values. How to return count of matches from my DAO methods?

Which approach rather?

1) Make property "lastQueryMatches" in DAO class
2) Return custom collection
3) Return composite object which contains List and matches property
4) Make different methods?
5) Anything else?

I'm not sure I understand your question and your different approaches right.
I'm using separate methods for getting the count of a query and the result of a query.
Then for pagination the client code may store the count or not, for example to have
an upper limit for the max index but that's quite unimportant for the server part.
The client simply request one page after another, e.g. using a method like this:
List<Article> fetchBy(String name, ..., Integer start, Integer max);
where start and max would be optional.
For complex searches and in order to be able to cache results for similiar queries I do
use Objects which contain all the search parameters and the count but this is just
for checking the upper limit. They never contain the result.

Hope that helps a litte bit...

could you explain a bit more your requirement? I'm not sure I understand what it is you are trying to achieve.

thanks,
- Savvas