how about the Structure of file which is exported blend2java

how about the Stucture of each file which is exported by blend2java?
because i create objects with multiple materials. then i export it to xml or gzip exporter . so it have multiple file but i don’t know about structure of files.

i think it contains vertex, line, polygon , material and texture. i think right or not?

if it not, can you explain me ?
thanks before.