Don't know but you might be better off using String.format to justify your output.

I have some ideas how to go around this issue, but I'm still surprised that "tab" character looks like single "space" character.
Option 1 is to split received line using '\t' into data fields, to measure length of each data field and finally to place the right amount of "space"s between them. This is resource consuming solution.

" I'm still surprised that "tab" character looks like single "space" character."
I think it is a sensible default, in the absence of ways to define a tab width.

" Option 1 [...] This is resource consuming solution."
Not really, that's probably what would be done by a real implementation anyway. And I doubt it would take more than a few milliseconds. It would consume your time resource, though...

Now, perhaps Option 2 is better in your case, doing the formatting at the source would avoid to decompose the string after receiving it. But it will make more data to send... Probably not a real issue.

Thank you, I'm still new in processing/java and it's good to find that I'm going in right direction.

I'm not sure yet how many data will be processed by this application/sketch and that's why I'll keep it as simple as possible. Option 2 is already implemented and the overhead caused by alignment is not significant.

Thanks :-)