java.io

Class OutputStream

java.lang.Object

java.io.OutputStream

All Implemented Interfaces:

Closeable, Flushable

Direct Known Subclasses:

ByteArrayOutputStream, FileOutputStream, FilterOutputStream, PipedOutputStream, PrintStream

public abstract class OutputStream
extends Object
implements Closeable, Flushable

This abstract class forms the base of the hierarchy of classes that write output as a stream of bytes. It provides a common set of methods for writing bytes to stream. Subclasses implement and/or extend these methods to write bytes in a particular manner or to a particular destination such as a file on disk or network connection.

Author:

Aaron M. Renn (arenn@urbanophile.com), Tom Tromey (tromey@cygnus.com)

Constructor Summary

Constructors

Constructor and Description
OutputStream() This is the default no-argument constructor for this class.

Method Summary

Modifier and Type	Method and Description
void	close() This method closes the stream.
void	flush() This method forces any data that may have been buffered to be written to the underlying output device.
void	write(byte[] b) This method all the writes bytes from the passed array to the output stream.
void	write(byte[] b, int off, int len) This method writes len bytes from the specified array b starting at index off into the array.
abstract void	write(int b) This method writes a single byte to the output stream.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OutputStream

public OutputStream()

This is the default no-argument constructor for this class. This method does nothing in this class.

Method Detail

close

public void close()
           throws IOException

This method closes the stream. Any internal or native resources associated with this stream are freed. Any subsequent attempt to access the stream might throw an exception.

This method in this class does nothing.

Specified by:

close in interface Closeable

Throws:

IOException - If an error occurs

flush

public void flush()
           throws IOException

This method forces any data that may have been buffered to be written to the underlying output device. Please note that the host environment might perform its own buffering unbeknowst to Java. In that case, a write made (for example, to a disk drive) might be cached in OS buffers instead of actually being written to disk.

This method in this class does nothing.

Specified by:

flush in interface Flushable

Throws:

IOException - If an error occurs

write

public void write(byte[] b)
           throws IOException,
                  NullPointerException

This method all the writes bytes from the passed array to the output stream. This method is equivalent to write(b, 0, buf.length) which is exactly how it is implemented in this class.

Parameters:

b - The array of bytes to write

Throws:

IOException - If an error occurs

NullPointerException

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException,
                  NullPointerException,
                  IndexOutOfBoundsException

This method writes len bytes from the specified array b starting at index off into the array.

This method in this class calls the single byte write() method in a loop until all bytes have been written. Subclasses should override this method if possible in order to provide a more efficent implementation.

Parameters:

b - The array of bytes to write from

off - The index into the array to start writing from

len - The number of bytes to write

Throws:

IOException - If an error occurs

NullPointerException

IndexOutOfBoundsException

write

public abstract void write(int b)
                    throws IOException

This method writes a single byte to the output stream. The byte written is the low eight bits of the int passed and a argument.

Subclasses must provide an implementation of this abstract method

Parameters:

b - The byte to be written to the output stream, passed as the low eight bits of an int

Throws:

IOException - If an error occurs