OutputStream

A Java int uses patterns of 32 bits to represent integers. The exact pattern from an int can be written to four bytes of a file. OutputStream is an abstract class from which all byte-oriented output streams descend. Its descendant classes are used for general-purpose (non-character output). These streams write groups of bytes to output destinations. Java writes the same format for primitive types on all platforms. The data in a binary file can be read by Java programs running on any platform.

A FileOuputStream connects an output stream of bytes to a file. A DataOuputStream can be connected to a FileOutputStream to provide methods that are convenient for writing various data types.