PURE Java™ 2

Required Methods

There are three kinds of Java programs: applications, Applets, and Servlets. Servlets are outside the scope of this book. Applets will be considered in Chapter 9, "GUI Programming II: Applets." Here, I will focus only on applications. Every Java application—but not class—must have a method that looks like the one in listing 3.3.

Code Listing 3.3. Source File with the main Method Defined

public class LibraryCard { String borrowerName; float fines; public static void main(String[] args) { System.exit(0); // The proper (but optional) method // to exit a Java application } }

The only required method is main. It has several important parts to its signature:

• public—This part of its signature grants access to this method from anywhere. ...