Java tutorial
/* * Copyright (c) 2000, 2005, 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. * * <p> Only one write operation upon a writable channel may be in progress at * any given time. If one thread initiates a write operation upon a channel * then any other thread that attempts to initiate another write operation will * block until the first operation is complete. Whether or not other kinds of * I/O operations may proceed concurrently with a write operation depends upon * the type of the channel. </p> * * * @author Mark Reinhold * @author JSR-51 Expert Group * @since 1.4 */ public interface WritableByteChannel extends Channel { /** * Writes a sequence of bytes to this channel from the given buffer. * * <p> An attempt is made to write up to <i>r</i> bytes to the channel, * where <i>r</i> is the number of bytes remaining in the buffer, that is, * {@code src.remaining()}, at the moment this method is invoked. * * <p> Suppose that a byte sequence of length <i>n</i> is written, where * {@code 0} {@code <=} <i>n</i> {@code <=} <i>r</i>. * This byte sequence will be transferred from the buffer starting at index * <i>p</i>, where <i>p</i> is the buffer's position at the moment this * method is invoked; the index of the last byte written will be * <i>p</i> {@code +} <i>n</i> {@code -} {@code 1}. * Upon return the buffer's position will be equal to * <i>p</i> {@code +} <i>n</i>; its limit will not have changed. * * <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 src * The buffer 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 int write(ByteBuffer src) throws IOException; }