Documentation  › java.io  › FilterOutputStream
 
 


  FilterOutputStream
  public

  Inherits From:   OutputStream : Object
  Conforms To:   none
  Declared In:   java.io


Class Description
 
This class is the superclass of all classes that filter output streams. These streams sit on top of an already existing output stream (the underlying output stream) which it uses as its basic sink of data, but possibly transforming the data along the way or providing additional functionality.

The class FilterOutputStream itself simply overrides all methods of OutputStream with versions that pass all requests to the underlying output stream. Subclasses of FilterOutputStream may further override some of these methods as well as provide additional methods and fields.



Class Variables
 
None declared in this class.


Instance Variables
 
out
protected OutputStream

The underlying output stream to be filtered.


Constructors
 
FilterOutputStream
public FilterOutputStream( OutputStream out )

Creates an output stream filter built on top of the specified underlying output stream.


Class Methods
 
None declared in this class.


Instance Methods
 
close
public void close( ) throws IOException

Closes this output stream and releases any system resources associated with the stream.

The close method of FilterOutputStream calls its flush method, and then calls the close method of its underlying output stream.


flush
public void flush( ) throws IOException

Flushes this output stream and forces any buffered output bytes to be written out to the stream.

The flush method of FilterOutputStream calls the flush method of its underlying output stream.


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

Writes b.length bytes to this output stream.

The write method of FilterOutputStream calls its write method of three arguments with the arguments b, 0, and b.length.

Note that this method does not call the one-argument write method of its underlying stream with the single argument b.


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

Writes len bytes from the specified byte array starting at offset off to this output stream.

The write method of FilterOutputStream calls the write method of one argument on each byte to output.

Note that this method does not call the write method of its underlying input stream with the same arguments. Subclasses of FilterOutputStream should provide a more efficient implementation of this method.


write
public void write( int b ) throws IOException

Writes the specified byte to this output stream.

The write method of FilterOutputStream calls the write method of its underlying output stream, that is, it performs out.write(b).

Implements the abstract write method of OutputStream.



Known Subclasses
 
PrintStream



 
 
  dydoc
  3/9/05