Reader r = new Reader();
r.getString();
Thats in your test01 file of course. Thats called creating an
instance of a class.
edit:
I misread your code, i didnt notice that getString was static:
However that wont work, since the line:
private static BufferedReader stdin =
new BufferedReader( new InputStreamReader( System.in ) );
will never be executed, stdin is going to be null.