what is the estension for Java load files

Answer 1

.java = Java programming;
.c = C programming;
.cpp = C++ programming;
.js = Javascript;
.pys = Python programming;

Answer 2

What do you mean by "Java load file"?

Files containing your source code have the .java extension.
Compiled files have the .class extension.

Answer 3

if you are talking about simple file then it can be of
.txt,. json and many more extended file which can be a media file also but if you are talking source code file extension then it is. java and that is of byte code it is .class