mirror of git://gcc.gnu.org/git/gcc.git
368 lines
13 KiB
Java
368 lines
13 KiB
Java
/* FileChannel.java --
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Copyright (C) 2002 Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.nio.channels;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import java.nio.MappedByteBuffer;
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import java.nio.channels.spi.AbstractInterruptibleChannel;
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/**
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* @author Michael Koch
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* @since 1.4
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*/
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public abstract class FileChannel extends AbstractInterruptibleChannel
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implements ByteChannel, GatheringByteChannel, ScatteringByteChannel
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{
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public static class MapMode
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{
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int m;
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public static final MapMode READ_ONLY = new MapMode(0);
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public static final MapMode READ_WRITE = new MapMode(1);
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public static final MapMode PRIVATE = new MapMode(2);
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/**
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* Initializes the MapMode.
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*/
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MapMode(int a)
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{
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m = a;
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}
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/**
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* Returns a string representation of the <code>MapMode</code> object.
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*/
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public String toString()
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{
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if (this == READ_ONLY)
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return "READ_ONLY";
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else if (this == READ_WRITE)
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return "READ_WRITE";
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return "PRIVATE";
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}
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}
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/**
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* Initializes the channel.
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*/
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protected FileChannel()
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{
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}
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/**
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* Maps the file into the memory.
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*
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* @exception IllegalArgumentException If the preconditions on the parameters
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* do not hold.
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* @exception IOException If an I/O error occurs.
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* @exception NonReadableChannelException If mode is READ_ONLY but this channel was
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* not opened for reading.
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* @exception NonWritableChannelException If mode is READ_WRITE or PRIVATE but this
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* channel was not opened for writing.
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*/
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public abstract MappedByteBuffer map(MapMode mode, long position, long size)
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throws IOException;
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/**
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* Return the size of the file thus far
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*
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* @exception ClosedChannelException If this channel is closed.
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*/
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public abstract long size() throws IOException;
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/**
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* Writes data to the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public final long write(ByteBuffer[] srcs) throws IOException
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{
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long result = 0;
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for (int i = 0; i < srcs.length; i++)
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result += write(srcs[i]);
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return result;
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}
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/**
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* Writes data to the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public abstract int write(ByteBuffer src) throws IOException;
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/**
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* Writes data to the channel.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedByInterruptException If another thread interrupts the
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* current thread while the transfer is in progress, thereby closing both
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* channels and setting the current thread's interrupt status.
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If position is negative.
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* @exception IOException If an I/O error occurs.
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* @exception NonWritableChannelException If this channel was not opened for
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* writing.
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*/
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public abstract int write(ByteBuffer srcs, long position)
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throws IOException;
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/**
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* Writes data to the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public abstract long write(ByteBuffer[] srcs, int offset, int length)
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throws IOException;
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/**
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* Reads data from the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public abstract long read(ByteBuffer[] dsts, int offset, int length)
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throws IOException;
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/**
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* Reads data from the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public final long read(ByteBuffer[] dsts) throws IOException
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{
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long result = 0;
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for (int i = 0; i < dsts.length; i++)
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read(dsts[i]);
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return result;
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}
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/**
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* Reads data from the channel.
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*
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* @exception IOException If an I/O error occurs.
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*/
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public abstract int read(ByteBuffer dst) throws IOException;
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/**
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* Reads data from the channel.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedByInterruptException If another thread interrupts the
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* current thread while the transfer is in progress, thereby closing both
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* channels and setting the current thread's interrupt status.
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If position is negative.
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* @exception IOException If an I/O error occurs.
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* @exception NonReadableChannelException If this channel was not opened for
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* reading.
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*/
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public abstract int read(ByteBuffer dst, long position)
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throws IOException;
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/**
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* Closes the channel.
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*
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* This is called from @see close.
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*
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* @exception IOException If an I/O error occurs.
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*/
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protected abstract void implCloseChannel() throws IOException;
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/**
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* msync with the disk
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IOException If an I/O error occurs.
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*/
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public abstract void force(boolean metaData) throws IOException;
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/**
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* Creates a file lock for the whole assoziated file.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedChannelException If this channel is closed.
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* @exception FileLockInterruptionException If the invoking thread is
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* interrupted while blocked in this method.
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* @exception IOException If an I/O error occurs.
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* @exception NonReadableChannelException If shared is true and this channel
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* was not opened for reading.
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* @exception NonWritableChannelException If shared is false and this channel
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* was not opened for writing.
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* @exception OverlappingFileLockException If a lock that overlaps the
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* requested region is already held by this Java virtual machine, or if
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* another thread is already blocked in this method and is attempting to lock
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* an overlapping region.
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*/
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public final FileLock lock() throws IOException
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{
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return lock(0, Long.MAX_VALUE, false);
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}
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/**
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* Creates a file lock for a region of the assoziated file.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedChannelException If this channel is closed.
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* @exception FileLockInterruptionException If the invoking thread is
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* interrupted while blocked in this method.
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* @exception IllegalArgumentException If the preconditions on the parameters
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* do not hold.
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* @exception IOException If an I/O error occurs.
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* @exception OverlappingFileLockException If a lock that overlaps the
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* requested region is already held by this Java virtual machine, or if
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* another thread is already blocked in this method and is attempting to lock
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* an overlapping region.
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* @exception NonReadableChannelException If shared is true and this channel
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* was not opened for reading.
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* @exception NonWritableChannelException If shared is false and this channel
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* was not opened for writing.
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*/
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public abstract FileLock lock(long position, long size, boolean shared)
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throws IOException;
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/**
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* Tries to aqquire alock on the whole assoziated file.
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IOException If an I/O error occurs.
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* @exception OverlappingFileLockException If a lock that overlaps the
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* requested region is already held by this Java virtual machine, or if
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* another thread is already blocked in this method and is attempting to lock
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* an overlapping region.
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*/
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public final FileLock tryLock() throws IOException
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{
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return tryLock(0, Long.MAX_VALUE, false);
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}
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/**
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* Tries to aqquire a lock on a region of the assoziated file.
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If the preconditions on the parameters
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* do not hold.
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* @exception IOException If an I/O error occurs.
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* @exception OverlappingFileLockException If a lock that overlaps the
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* requested region is already held by this Java virtual machine, or if
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* another thread is already blocked in this method and is attempting to lock
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* an overlapping region.
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*/
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public abstract FileLock tryLock(long position, long size, boolean shared)
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throws IOException;
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/**
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* Returns the current position on the file.
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IOException If an I/O error occurs.
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*/
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public abstract long position() throws IOException;
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/**
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* Sets the position of the channel on the assoziated file.
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If newPosition is negative.
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* @exception IOException If an I/O error occurs.
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*/
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public abstract FileChannel position(long newPosition)
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throws IOException;
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/**
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* Transfers bytes from this channel's file to the given writable byte
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* channel.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedByInterruptException If another thread interrupts the
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* current thread while the transfer is in progress, thereby closing both
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* channels and setting the current thread's interrupt status.
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If the preconditions on the parameters
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* do not hold.
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* @exception IOException If an I/O error occurs.
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* @exception NonReadableChannelException If this channel was not opened for
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* reading.
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* @exception NonWritableChannelException If the target channel was not
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* opened for writing.
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*/
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public abstract long transferTo(long position, long count,
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WritableByteChannel target)
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throws IOException;
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/**
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* Transfers bytes from the given readable channel into this channel.
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*
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* @exception AsynchronousCloseException If another thread closes this channel
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* while the transfer is in progress.
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* @exception ClosedByInterruptException If another thread interrupts the
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* current thread while the transfer is in progress, thereby closing both
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* channels and setting the current thread's interrupt status.
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If the preconditions on the parameters
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* do not hold.
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* @exception IOException If an I/O error occurs.
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* @exception NonReadableChannelException If the source channel was not
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* opened for reading.
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* @exception NonWritableChannelException If this channel was not opened for
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* writing.
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*/
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public abstract long transferFrom(ReadableByteChannel src, long position,
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long count) throws IOException;
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/**
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* Truncates the channel's file at <code>size</code>.
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*
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* @exception ClosedChannelException If this channel is closed.
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* @exception IllegalArgumentException If size is negative.
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* @exception IOException If an I/O error occurs.
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* @exception NonWritableChannelException If this channel was not opened for
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* writing.
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*/
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public abstract FileChannel truncate(long size) throws IOException;
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}
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