How are Stata .dta files encoded?

Question

I am trying to write a parser for Stata's .dta file format (in Java, but I don't think that's relevant for this question). I have already found the information about the file format per se here, but my problem is that when I open the file in Notepad or when I read it with BufferedReader / FileReader in Java, all I get (for this sample file) is the following:

I am aware of other questions on StackOverflow that concern opening Stata files without Stata and am indeed able to do so in R (see e.g. Convert Stata .dta file to CSV without Stata software), but I have not yet found an answer to my particular question anywhere. In fact, I suspect that the question is more I/O-related than Stata-related. (In case it is relevant, the above result was produced using NetBeans 8.2 on Windows 10.)