001 /*
002 * Copyright 2000-2005 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.nio.channels;
027
028 import java.io.IOException;
029 import java.nio.ByteBuffer;
030
031 /**
032 * A channel that can write bytes.
033 *
034 * <p> Only one write operation upon a writable channel may be in progress at
035 * any given time. If one thread initiates a write operation upon a channel
036 * then any other thread that attempts to initiate another write operation will
037 * block until the first operation is complete. Whether or not other kinds of
038 * I/O operations may proceed concurrently with a write operation depends upon
039 * the type of the channel. </p>
040 *
041 *
042 * @author Mark Reinhold
043 * @author JSR-51 Expert Group
044 * @version 1.23, 07/05/05
045 * @since 1.4
046 */
047
048 public interface WritableByteChannel extends Channel {
049
050 /**
051 * Writes a sequence of bytes to this channel from the given buffer.
052 *
053 * <p> An attempt is made to write up to <i>r</i> bytes to the channel,
054 * where <i>r</i> is the number of bytes remaining in the buffer, that is,
055 * <tt>src.remaining()</tt>, at the moment this method is invoked.
056 *
057 * <p> Suppose that a byte sequence of length <i>n</i> is written, where
058 * <tt>0</tt> <tt><=</tt> <i>n</i> <tt><=</tt> <i>r</i>.
059 * This byte sequence will be transferred from the buffer starting at index
060 * <i>p</i>, where <i>p</i> is the buffer's position at the moment this
061 * method is invoked; the index of the last byte written will be
062 * <i>p</i> <tt>+</tt> <i>n</i> <tt>-</tt> <tt>1</tt>.
063 * Upon return the buffer's position will be equal to
064 * <i>p</i> <tt>+</tt> <i>n</i>; its limit will not have changed.
065 *
066 * <p> Unless otherwise specified, a write operation will return only after
067 * writing all of the <i>r</i> requested bytes. Some types of channels,
068 * depending upon their state, may write only some of the bytes or possibly
069 * none at all. A socket channel in non-blocking mode, for example, cannot
070 * write any more bytes than are free in the socket's output buffer.
071 *
072 * <p> This method may be invoked at any time. If another thread has
073 * already initiated a write operation upon this channel, however, then an
074 * invocation of this method will block until the first operation is
075 * complete. </p>
076 *
077 * @param src
078 * The buffer from which bytes are to be retrieved
079 *
080 * @return The number of bytes written, possibly zero
081 *
082 * @throws NonWritableChannelException
083 * If this channel was not opened for writing
084 *
085 * @throws ClosedChannelException
086 * If this channel is closed
087 *
088 * @throws AsynchronousCloseException
089 * If another thread closes this channel
090 * while the write operation is in progress
091 *
092 * @throws ClosedByInterruptException
093 * If another thread interrupts the current thread
094 * while the write operation is in progress, thereby
095 * closing the channel and setting the current thread's
096 * interrupt status
097 *
098 * @throws IOException
099 * If some other I/O error occurs
100 */
101 public int write(ByteBuffer src) throws IOException;
102
103 }
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