🚀 go-pugleaf

I'm having problems figuring out how to read in a file written using a C++
program.  The file is a sort of ring buffer that has a header at the
beginning of the file, and then the ring buffer is after that.   The header
is a C structure that has a lot of fields in it.  I need a way to first be
able to read that header into a header on the java side which is a class
that is just like the C struct.  RandomAccessFiles read(byte[]) is what I
thought I could use by typecasting my java class that I want to fill in to a
byte[], but the typecast won't go.  Please don't tell me I'll have to fill
in each field of that class with an individual call like ReadInt, ReadLong,
etc.  That would seem to be really inefficient, and not to mention
unnecessary coding.

I also need to be able get the size of the header (I used sizeof in C) so I
can seek forwards and backwards in the ring buffer.  I could calculate the
size of this class (struct) myself but first of all it has a lot of elements
and one of the elements is another structure which has a lot of elements
itself, and second of all what if the structure size changes (and it most
certainly will) then I have to recalculate this all over again, why the hell
isn't there a sizeof function just for this reason (and more that I've run
into)?

Java isn't looking to be able to do what I could do in C with no problems,
what gives here?