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java.io
public class: FilterOutputStream [javadoc | source]
java.lang.Object
   java.io.OutputStream
      java.io.FilterOutputStream

All Implemented Interfaces:
    Flushable, Closeable

Direct Known Subclasses:
    JarOutputStream, BufferedOutputStream, PrintStream, DigestOutputStream, CipherOutputStream, GZIPOutputStream, LogStream, ZipOutputStream, DataOutputStream, CheckedOutputStream, InflaterOutputStream, DeflaterOutputStream

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.

Field Summary
protected  OutputStream out    The underlying output stream to be filtered. 
Constructor:
 public FilterOutputStream(OutputStream out) 
    Creates an output stream filter built on top of the specified underlying output stream.
    Parameters:
    out - the underlying output stream to be assigned to the field this.out for later use, or null if this instance is to be created without an underlying stream.
Method from java.io.FilterOutputStream Summary:
close,   flush,   write,   write,   write
Methods from java.io.OutputStream:
close,   flush,   write,   write,   write
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.io.FilterOutputStream Detail:
 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.

 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.

 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.

 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.

 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.