Packages  This Package  Prev  Next  Index  

§2.12 Class FilterOutputStream

public  class  java.io.FilterOutputStream
    extends  java.io.OutputStream  (I-§2.15)
{
// Fields protected OutputStream out; §2.12.1 // Constructors public FilterOutputStream(OutputStream out); §2.12.2 // Methods public void close(); §2.12.3 public void flush(); §2.12.4 public void write(byte b[]); §2.12.5 public void write(byte b[], int off, int len); §2.12.6 public void write(int b); §2.12.7 }
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), but provide 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.


Fields

out

protected OutputStream out
The underlying output stream.

Constructors

FilterOutputStream

public FilterOutputStream(OutputStream out)
Creates an output stream filter built on top of the specified underlying output stream.
Parameters:
out - the underlying output stream

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 (I-§2.12.4), and then calls the close method of its underlying output stream (I-§2.12.1).

Throws
IOException (I-§2.29)
If an I/O error occurs.
Overrides:
close in class OutputStream (I-§2.15.2).

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 it underlying output stream (I-§2.12.1).

Throws
IOException (I-§2.29)
If an I/O error occurs.
Overrides:
flush in class OutputStream (I-§2.15.3).

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 (I-§2.12.6) 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.
Parameters:
b - the data to be written
Throws
IOException (I-§2.29)
If an I/O error occurs.
Overrides:
write in class OutputStream (I-§2.15.4).

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 (I-§2.12.7) 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.
Parameters:
b - the data
off - the start offset in the data
len - the number of bytes to write
Throws
IOException (I-§2.29)
If an I/O error occurs.
Overrides:
write in class OutputStream (I-§2.15.5).

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(I-§2.12.1).

Parameters:
b - the byte
Throws
IOException (I-§2.29)
If an I/O error occurs.
Overrides:
write in class OutputStream (I-§2.15.6).

Packages  This Package  Prev  Next  Index
Java API Document (HTML generated by dkramer on April 22, 1996)
Copyright © 1996 Sun Microsystems, Inc. All rights reserved
Please send any comments or corrections to doug.kramer@sun.com