Java is not a programming language, that creates executable programs by itself, but bytecode
that the Java Virtual Machine runs.
Thats one of the reasons why you cant just implement 3dgs into Java, or the other way around.

Lite-C is actually the Programming Language C with specific addons+functionalites.
So learning Lite-C, you can program C.
Most games a few yers ago where programed in C.

If you want to stick to Java, concentrate on something else.
Mobile Gaming is a good field for example.