The idea was to be able to insert Cyrillic characters into mysql DB. The problem was that I was using JPA eclipse-link. It took me some time and a lot of nerves to find the solution. Just add to the persistence.xml, to the url property like this:
Note the ? sign, not &! And don’t use useEncoding, it will not work. Only like this one.
fuck blogger.com for not allowing pasting source code.