| /* |
| * Copyright (c) 2000, 2006, 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 |
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| * questions. |
| */ |
| |
| package java.nio.channels; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| |
| /** |
| * A channel that can read bytes into a sequence of buffers. |
| * |
| * <p> A <i>scattering</i> read operation reads, in a single invocation, a |
| * sequence of bytes into one or more of a given sequence of buffers. |
| * Scattering reads 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>gathering</i> write operations are defined in the {@link |
| * GatheringByteChannel} interface. </p> |
| * |
| * |
| * @author Mark Reinhold |
| * @author JSR-51 Expert Group |
| * @since 1.4 |
| */ |
| |
| public interface ScatteringByteChannel |
| extends ReadableByteChannel |
| { |
| |
| /** |
| * Reads a sequence of bytes from this channel into a subsequence of the |
| * given buffers. |
| * |
| * <p> An invocation of this method attempts to read up to <i>r</i> bytes |
| * from this channel, where <i>r</i> is the total number of bytes remaining |
| * the specified subsequence of the given buffer array, that is, |
| * |
| * <blockquote><pre> |
| * dsts[offset].remaining() |
| * + dsts[offset+1].remaining() |
| * + ... + dsts[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 read, where |
| * <tt>0</tt> <tt><=</tt> <i>n</i> <tt><=</tt> <i>r</i>. |
| * Up to the first <tt>dsts[offset].remaining()</tt> bytes of this sequence |
| * are transferred into buffer <tt>dsts[offset]</tt>, up to the next |
| * <tt>dsts[offset+1].remaining()</tt> bytes are transferred into buffer |
| * <tt>dsts[offset+1]</tt>, and so forth, until the entire byte sequence |
| * is transferred into the given buffers. As many bytes as possible are |
| * transferred into 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> This method may be invoked at any time. If another thread has |
| * already initiated a read operation upon this channel, however, then an |
| * invocation of this method will block until the first operation is |
| * complete. </p> |
| * |
| * @param dsts |
| * The buffers into which bytes are to be transferred |
| * |
| * @param offset |
| * The offset within the buffer array of the first buffer into |
| * which bytes are to be transferred; must be non-negative and no |
| * larger than <tt>dsts.length</tt> |
| * |
| * @param length |
| * The maximum number of buffers to be accessed; must be |
| * non-negative and no larger than |
| * <tt>dsts.length</tt> - <tt>offset</tt> |
| * |
| * @return The number of bytes read, possibly zero, |
| * or <tt>-1</tt> if the channel has reached end-of-stream |
| * |
| * @throws IndexOutOfBoundsException |
| * If the preconditions on the <tt>offset</tt> and <tt>length</tt> |
| * parameters do not hold |
| * |
| * @throws NonReadableChannelException |
| * If this channel was not opened for reading |
| * |
| * @throws ClosedChannelException |
| * If this channel is closed |
| * |
| * @throws AsynchronousCloseException |
| * If another thread closes this channel |
| * while the read operation is in progress |
| * |
| * @throws ClosedByInterruptException |
| * If another thread interrupts the current thread |
| * while the read 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 read(ByteBuffer[] dsts, int offset, int length) |
| throws IOException; |
| |
| /** |
| * Reads a sequence of bytes from this channel into the given buffers. |
| * |
| * <p> An invocation of this method of the form <tt>c.read(dsts)</tt> |
| * behaves in exactly the same manner as the invocation |
| * |
| * <blockquote><pre> |
| * c.read(dsts, 0, dsts.length);</pre></blockquote> |
| * |
| * @param dsts |
| * The buffers into which bytes are to be transferred |
| * |
| * @return The number of bytes read, possibly zero, |
| * or <tt>-1</tt> if the channel has reached end-of-stream |
| * |
| * @throws NonReadableChannelException |
| * If this channel was not opened for reading |
| * |
| * @throws ClosedChannelException |
| * If this channel is closed |
| * |
| * @throws AsynchronousCloseException |
| * If another thread closes this channel |
| * while the read operation is in progress |
| * |
| * @throws ClosedByInterruptException |
| * If another thread interrupts the current thread |
| * while the read 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 read(ByteBuffer[] dsts) throws IOException; |
| |
| } |
