Problems with FileDownloader

I just want to create and download a xls-file when the user klicks a button. But I got a few problems with the fileDownloader.

First, i couldn’t found any solution to set the name of the downloaded file to the name of the generated file.

Then, sometimes (i think every second time) i click that button, the vaadin loading spinner is not shown. But i have to avoid the user to click the button again (because the creation of the file has already begun…).

Last, i would like to show an error-message or something else, if a problem occurs while the file is created.

Can somone help me with these problems?