/* * Copyright (c) 2004 - 2011 Eike Stepper (Berlin, Germany) and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Eike Stepper - initial API and implementation */ package org.eclipse.net4j.util.io; import java.io.IOException; import java.io.OutputStream; /** * 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 DelegatingOutputStream
itself simply overrides all methods of OutputStream
with
* versions that pass all requests to the underlying output stream. Subclasses of DelegatingOutputStream
* may further override some of these methods as well as provide additional methods and fields.
*
* Note: The only difference to {@link java.io.FilterOutputStream} is that DelegatingOutputStream
* does not override {@link #write(byte[])} or {@link #write(byte[], int, int)} but rather exposes the original
* implementations of InputStream
which call {@link #write(int)} instead of their delegate counterparts.
*
* @author Eike Stepper
*/
public class DelegatingOutputStream 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 DelegatingOutputStream(OutputStream out)
{
this.out = out;
}
public OutputStream getDelegate()
{
return out;
}
/**
* Writes the specified byte
to this output stream.
*
* The write
method of DelegatingOutputStream
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.
*/
@Override
public void write(int b) throws IOException
{
out.write(b);
}
/**
* Flushes this output stream and forces any buffered output bytes to be written out to the stream.
*
* The flush
method of DelegatingOutputStream
calls the flush
method of its
* underlying output stream.
*
* @exception IOException
* if an I/O error occurs.
* @see DelegatingOutputStream#out
*/
@Override
public void flush() throws IOException
{
out.flush();
}
/**
* Closes this output stream and releases any system resources associated with the stream.
*
* The close
method of DelegatingOutputStream
calls its flush
method, and then
* calls the close
method of its underlying output stream.
*
* @exception IOException
* if an I/O error occurs.
* @see DelegatingOutputStream#flush()
* @see DelegatingOutputStream#out
*/
@Override
public void close() throws IOException
{
try
{
flush();
}
catch (IOException ignored)
{
}
out.close();
}
}