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	/*
	* Copyright (c) 1994, 2017, Oracle and/or its affiliates. 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.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 1.0
	*/
	public class FilterOutputStream extends OutputStream {
	/**
	* The underlying output stream to be filtered.
	*/
	protected OutputStream out;

	/**
	* Whether the stream is closed; implicitly initialized to false.
	*/
	private volatile boolean closed;

	/**
	* Object used to prevent a race on the 'closed' instance variable.
	*/
	private final Object closeLock = new Object();

	/**
	* 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 {@code this.out} 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 {@code out.write(b)}.
	* <p>
	* Implements the abstract {@code write} method of {@code OutputStream}.
	*
	* @param b the <code>byte</code>.
	* @exception IOException if an I/O error occurs.
	*/
	@Override
	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 output 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)
	*/
	@Override
	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 output 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)
	*/
	@Override
	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
	*/
	@Override
	public void flush() throws IOException {
	out.flush();
	}

	/**
	* Closes this output stream and releases any system resources
	* associated with the stream.
	* <p>
	* When not already closed, the {@code close} method of {@code
	* FilterOutputStream} calls its {@code flush} method, and then
	* calls the {@code 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
	*/
	@Override
	public void close() throws IOException {
	if (closed) {
	return;
	}
	synchronized (closeLock) {
	if (closed) {
	return;
	}
	closed = true;
	}

	Throwable flushException = null;
	try {
	flush();
	} catch (Throwable e) {
	flushException = e;
	throw e;
	} finally {
	if (flushException == null) {
	out.close();
	} else {
	try {
	out.close();
	} catch (Throwable closeException) {
	// evaluate possible precedence of flushException over closeException
	if ((flushException instanceof ThreadDeath) &&
	!(closeException instanceof ThreadDeath)) {
	flushException.addSuppressed(closeException);
	throw (ThreadDeath) flushException;
	}

	if (flushException != closeException) {
	closeException.addSuppressed(flushException);
	}

	throw closeException;
	}
	}
	}
	}
	}

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