package - keyword with the package name in top of your source file:
package mygraphics;
public class Circle {
}
Circle.java is saved into directory called mygraphics.mygraphics> javac Circle.javamygraphics> java Circle Exception in thread "main" java.lang.NoClassDefFoundError: Circle (wrong name: mygraphics/Circle) at java.lang.ClassLoader.defineClass1(Native Method)
mygraphics> java mygraphics.Circle mygraphics> cd .. > java mygraphics.Circle
com.companyname.package, fi.tamk.mygraphics, fi.uta.mygraphicsmygraphics.Circle a = new mygraphics.Circle()import mygraphics.*;import mygraphics.Circle