Java For Dummies Quick Reference

DataOutputStream Class

Package: java.io

The DataOutputStream class is the main class you’ll work with for writing data to binary files. This class builds on the BufferedOutputStream class by adding the ability to write primitive data types. The BufferedOutputStream class builds on the FileOutputStream class by adding buffered output for the sake of efficiency. And the FileOutputStream class provides the basic capabilities of writing characters to an output stream.

The DataOutputStream class is one of many Java I/O classes that use streams. For more information, see Streams (Overview).

Constructor

Constructor	Description
DataOutputStream (OutputStream out)	Creates a data output stream for the specified output stream.

Methods

Method	Description
void close()	Closes the file.
void flush()	Writes the contents of the buffer to the hard drive.
int size()	Returns the number of bytes written to the file.
void writeBoolean (boolean value)	Writes a boolean value to the output stream. It throws IOException.
void writeByte (byte value)	Writes a byte value to the output stream. It throws IOException.
void writeChar(char value)	Writes a char value to the output stream. It throws IOException.
void writeDouble(double value)	Writes a double value to the output stream. It throws IOException.
void writeFloat(float value) ...