Back to index...

	/*
	* Copyright (c) 2000, 2001, 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.nio.channels;

	import java.io.IOException;
	import java.nio.ByteBuffer;


	/**
	* A channel that can write bytes from a sequence of buffers.
	*
	* <p> A <i>gathering</i> write operation writes, in a single invocation, a
	* sequence of bytes from one or more of a given sequence of buffers.
	* Gathering writes are often useful when implementing network protocols or
	* file formats that, for example, group data into segments consisting of one
	* or more fixed-length headers followed by a variable-length body. Similar
	* <i>scattering</i> read operations are defined in the {@link
	* ScatteringByteChannel} interface. </p>
	*
	*
	* @author Mark Reinhold
	* @author JSR-51 Expert Group
	* @since 1.4
	*/

	public interface GatheringByteChannel
	extends WritableByteChannel
	{

	/**
	* Writes a sequence of bytes to this channel from a subsequence of the
	* given buffers.
	*
	* <p> An attempt is made to write up to <i>r</i> bytes to this channel,
	* where <i>r</i> is the total number of bytes remaining in the specified
	* subsequence of the given buffer array, that is,
	*
	* <blockquote><pre>
	* srcs[offset].remaining()
	* + srcs[offset+1].remaining()
	* + ... + srcs[offset+length-1].remaining()</pre></blockquote>
	*
	* at the moment that this method is invoked.
	*
	* <p> Suppose that a byte sequence of length <i>n</i> is written, where
	* <tt>0</tt> <tt><=</tt> <i>n</i> <tt><=</tt> <i>r</i>.
	* Up to the first <tt>srcs[offset].remaining()</tt> bytes of this sequence
	* are written from buffer <tt>srcs[offset]</tt>, up to the next
	* <tt>srcs[offset+1].remaining()</tt> bytes are written from buffer
	* <tt>srcs[offset+1]</tt>, and so forth, until the entire byte sequence is
	* written. As many bytes as possible are written from each buffer, hence
	* the final position of each updated buffer, except the last updated
	* buffer, is guaranteed to be equal to that buffer's limit.
	*
	* <p> Unless otherwise specified, a write operation will return only after
	* writing all of the <i>r</i> requested bytes. Some types of channels,
	* depending upon their state, may write only some of the bytes or possibly
	* none at all. A socket channel in non-blocking mode, for example, cannot
	* write any more bytes than are free in the socket's output buffer.
	*
	* <p> This method may be invoked at any time. If another thread has
	* already initiated a write operation upon this channel, however, then an
	* invocation of this method will block until the first operation is
	* complete. </p>
	*
	* @param srcs
	* The buffers from which bytes are to be retrieved
	*
	* @param offset
	* The offset within the buffer array of the first buffer from
	* which bytes are to be retrieved; must be non-negative and no
	* larger than <tt>srcs.length</tt>
	*
	* @param length
	* The maximum number of buffers to be accessed; must be
	* non-negative and no larger than
	* <tt>srcs.length</tt> - <tt>offset</tt>
	*
	* @return The number of bytes written, possibly zero
	*
	* @throws IndexOutOfBoundsException
	* If the preconditions on the <tt>offset</tt> and <tt>length</tt>
	* parameters do not hold
	*
	* @throws NonWritableChannelException
	* If this channel was not opened for writing
	*
	* @throws ClosedChannelException
	* If this channel is closed
	*
	* @throws AsynchronousCloseException
	* If another thread closes this channel
	* while the write operation is in progress
	*
	* @throws ClosedByInterruptException
	* If another thread interrupts the current thread
	* while the write operation is in progress, thereby
	* closing the channel and setting the current thread's
	* interrupt status
	*
	* @throws IOException
	* If some other I/O error occurs
	*/
	public long write(ByteBuffer[] srcs, int offset, int length)
	throws IOException;


	/**
	* Writes a sequence of bytes to this channel from the given buffers.
	*
	* <p> An invocation of this method of the form <tt>c.write(srcs)</tt>
	* behaves in exactly the same manner as the invocation
	*
	* <blockquote><pre>
	* c.write(srcs, 0, srcs.length);</pre></blockquote>
	*
	* @param srcs
	* The buffers from which bytes are to be retrieved
	*
	* @return The number of bytes written, possibly zero
	*
	* @throws NonWritableChannelException
	* If this channel was not opened for writing
	*
	* @throws ClosedChannelException
	* If this channel is closed
	*
	* @throws AsynchronousCloseException
	* If another thread closes this channel
	* while the write operation is in progress
	*
	* @throws ClosedByInterruptException
	* If another thread interrupts the current thread
	* while the write operation is in progress, thereby
	* closing the channel and setting the current thread's
	* interrupt status
	*
	* @throws IOException
	* If some other I/O error occurs
	*/
	public long write(ByteBuffer[] srcs) throws IOException;

	}

Back to index...