* 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.
*
* @author Jonathan Payne
* @since JDK1.0
*/
public
class FilterOutputStream extends OutputStream {
/**
* The underlying output stream to be filtered.
*/
protected OutputStream out;
/**
* Creates an output stream filter built on top of the specified
* underlying output stream.
*
* @param 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.
*/
public FilterOutputStream(OutputStream out) {
this.out = out;
}
/**
* 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.
*
* @param b the byte.
* @exception IOException if an I/O error occurs.
*/
public void write(int b) throws IOException {
out.write(b);
}
/**
* 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.
*
* @param b the data to be written.
* @exception IOException if an I/O error occurs.
* @see java.io.FilterOutputStream#write(byte[], int, int)
*/
public void write(byte b[]) throws IOException {
write(b, 0, b.length);
}
/**
* 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.
*
* @param b the data.
* @param off the start offset in the data.
* @param len the number of bytes to write.
* @exception IOException if an I/O error occurs.
* @see java.io.FilterOutputStream#write(int)
*/
public void write(byte b[], int off, int len) throws IOException {
if ((off | len | (b.length - (len + off)) | (off + len)) < 0)
throw new IndexOutOfBoundsException();
for (int i = 0 ; i < len ; i++) {
write(b[off + i]);
}
}
/**
* 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.
*
* @exception IOException if an I/O error occurs.
* @see java.io.FilterOutputStream#out
*/
public void flush() throws IOException {
out.flush();
}
/**
* 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.
*
* @exception IOException if an I/O error occurs.
* @see java.io.FilterOutputStream#flush()
* @see java.io.FilterOutputStream#out
*/
public void close() throws IOException {
try {
flush();
} catch (IOException ignored) {
}
out.close();
}
}