What are you using JAVA libraries for working with excel files?
Quite a long time, all of the required functionality was implemented using Apache POI. Recently there was a need to do some more complicated things within Excel and are faced with the problem of the lack of this library functionality... In particular: very primitive graphics only, no data types for cells (well i.e. you can specify something like a mask, but Excel does not see it as data type), for too long the merge operation (although that's in question here is probably just code optimization will save). If anyone has advice I would be grateful primnogo. I would like of course some serious free library with documentation, but paid can also be counted if they are worth it.