Java Text Output

So I'm working on a program right now and I'm saving the output to a text file from the command line like so:
java Program >> output.txt

However, this does not save error messages.
Is there a way to have it include error messages?

>>10
you can use whatever extension you want in GNU/Linux... .txt or otherwise, it makes no difference, really

you could do echo hurr > herp.derp and it's still a text file

I name my backup versions of config files *.*.BACK, and although it's not an official extension it doesn't matter at all
>>11
if I remember correctly, the only real difference is how they handle EOLs

but when saving a text file in a program such as, say, gedit (and yes, I know that's not a ``true'' text editor, fuck off) you can specify what kind of line ending to use