Chapter 10. Using I/O

The Java I/O system is based upon a hierarchy of classes and is very quite large, utilising many classes. It also has two complete systems, one for byte I/O and one for character I/O.

Java's I/O is Built upon Streams

Java programs perform I/O through streams, which is an abstraction that either produces or consumes information. All streams behave in the same manner no matter what they're connected to, which means the same I/O classes and methods can be applied to different types of input and outputs devices.

Byte Streams and Character Streams

Modern versions of Java define two types of I/O streams, byte and character. Byte streams provide a convenient means for handling input and output of bytes, typically used for reading/writing binary data and useful when reading/writing files. Character streams are designed for handling the I/O of characters using Unicode. At the lowest level, all I/O is still byte orientated.