JDK - The Java Developers Kit. We are going to start with a simple program that prints out a message and exits. This program is an application and is not designed to run inside of a browser. The public static void main is the main program. If one runs the file containing the firstClass it will be the main program that is executed.
System is a special object in Java.
It has an input and output stream associated with it and it always exists. The System.out.println is using a part of the System object called out and using the println method associated with out. It outputs a line of results or text. Building and Running the Routine in JWS Building and Running the Routine in CodeWarrior A Second Application. Variable Types Java has some primitive types that aren't full blown classes and all kinds of classes.