I wrote a program that creates a set of data that is outputted to an excel spreadsheet. I was originally using the jexcel library to write the data to the file, but I'd like to update the program so that it can check and see whether is should create a ".xls" or ".xlsx" file, then write to the appropriate document type. Apache POI seems to be the best option in terms of writing to a ".xlsx" file, but any ideas about determining the correct file type?
I could just have the user choose when naming the file, but that seems like extra work for the user and I'm assuming that there are users who don't know what file type they'd want.
Any ideas?
Also, I'm assuming the OS is windows and the user has some version of excel, in other cases I'll just choose a default file type.