I'm doing an assignment, and our lecturer sent us a class to start from but the problem is that it is .class not .java and I have a problem to integrate it in my project which I already started.

I tried to import from Library properties -- compile tab etc, and I thought it worked coz it appeared with the other .java files (which I don't know if it's a good thing or not), however when I tried to use it, I had an error cannot find symbol. symbol: constructor of the class I tried to import!

Can someone please tell me how to import a .class file step by step?

Thanks a lot in advance.
Naomi