/*
* Copyright 1994-1999 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package java.io;
/**
* This class is the superclass of all classes that filter output
* streams. These streams sit on top of an already existing output
* stream (the <i>underlying</i> output stream) which it uses as its
* basic sink of data, but possibly transforming the data along the
* way or providing additional functionality.
* <p>
* The class <code>FilterOutputStream</code> itself simply overrides
* all methods of <code>OutputStream</code> with versions that pass
* all requests to the underlying output stream. Subclasses of
* <code>FilterOutputStream</code> 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 <tt>this.out</tt> for later use, or
* <code>null</code> if this instance is to be
* created without an underlying stream.
*/
public FilterOutputStream(OutputStream out) {
this.out = out;
}
/**
* Writes the specified <code>byte</code> to this output stream.
* <p>
* The <code>write</code> method of <code>FilterOutputStream</code>
* calls the <code>write</code> method of its underlying output stream,
* that is, it performs <tt>out.write(b)</tt>.
* <p>
* Implements the abstract <tt>write</tt> method of <tt>OutputStream</tt>.
*
* @param b the <code>byte</code>.
* @exception IOException if an I/O error occurs.
*/
public void write(int b) throws IOException {
out.write(b);
}
/**
* Writes <code>b.length</code> bytes to this output stream.
* <p>
* The <code>write</code> method of <code>FilterOutputStream</code>
* calls its <code>write</code> method of three arguments with the
* arguments <code>b</code>, <code>0</code>, and
* <code>b.length</code>.
* <p>
* Note that this method does not call the one-argument
* <code>write</code> method of its underlying stream with the single
* argument <code>b</code>.
*
* @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 <code>len</code> bytes from the specified
* <code>byte</code> array starting at offset <code>off</code> to
* this output stream.
* <p>
* The <code>write</code> method of <code>FilterOutputStream</code>
* calls the <code>write</code> method of one argument on each
* <code>byte</code> to output.
* <p>
* Note that this method does not call the <code>write</code> method
* of its underlying input stream with the same arguments. Subclasses
* of <code>FilterOutputStream</code> 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.
* <p>
* The <code>flush</code> method of <code>FilterOutputStream</code>
* calls the <code>flush</code> 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.
* <p>
* The <code>close</code> method of <code>FilterOutputStream</code>
* calls its <code>flush</code> method, and then calls the
* <code>close</code> 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();
}
}