So my computer crashed while I was coding in eclipse. I turn it on and the class I was working on is absolutely empty, only one empty line

It wasn't a big class, but that still hurts

Me, an apprentice, got to contribute towards a project for the business.
I only have access to the git of that particular project, no access to the other projects, databases or sourcecodes.
Thing is, we basically have to redo an old programm to access and work with the database, so having access to the sourcecode of that or access to the database would be very very helpful.
I have to guess the attributenames of the tables and what the code looked like that assembled all the data together for the overview.
I feel incredibly unprepared for this.