For example, a Java program obtains file I/O (input/output) services by creating objects from various file-related classes in Java’s class library and calling their methods.

This article explores the I/O classes, interfaces, and operations provided by the Java platform. Written by Jeff Hanson, Contributor July 4, 2002 at 8:15 p.m. PT ...

In a previous Java 101 tutorial, you learned how to better organize your code by declaring reference types (also known as classes and interfaces) as members of other reference types and blocks.