Discover file mimetype

There is any way to get the file mimetype of a file?
I use file transfer to download files, and I need to try to open the file with fileopener, but I need to know the mimetype of the file, but I cound’t find any way to do that (I tried with file plugin, but Icound do it)

Thanks!

Any resolution on the same? Tried File.getFile but it only returns modifiedTime and size.