| /* FileChannel.java -- |
| Copyright (C) 2002 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.nio.channels; |
| |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| import java.nio.MappedByteBuffer; |
| import java.nio.channels.spi.AbstractInterruptibleChannel; |
| |
| |
| /** |
| * @author Michael Koch |
| * @since 1.4 |
| */ |
| public abstract class FileChannel extends AbstractInterruptibleChannel |
| implements ByteChannel, GatheringByteChannel, ScatteringByteChannel |
| { |
| public static class MapMode |
| { |
| int m; |
| public static final MapMode READ_ONLY = new MapMode(0); |
| public static final MapMode READ_WRITE = new MapMode(1); |
| public static final MapMode PRIVATE = new MapMode(2); |
| |
| /** |
| * Initializes the MapMode. |
| */ |
| MapMode(int a) |
| { |
| m = a; |
| } |
| |
| /** |
| * Returns a string representation of the <code>MapMode</code> object. |
| */ |
| public String toString() |
| { |
| if (this == READ_ONLY) |
| return "READ_ONLY"; |
| else if (this == READ_WRITE) |
| return "READ_WRITE"; |
| |
| return "PRIVATE"; |
| } |
| } |
| |
| /** |
| * Initializes the channel. |
| */ |
| protected FileChannel() |
| { |
| } |
| |
| /** |
| * Maps the file into the memory. |
| * |
| * @exception IllegalArgumentException If the preconditions on the parameters |
| * do not hold. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonReadableChannelException If mode is READ_ONLY but this channel was |
| * not opened for reading. |
| * @exception NonWritableChannelException If mode is READ_WRITE or PRIVATE but this |
| * channel was not opened for writing. |
| */ |
| public abstract MappedByteBuffer map(MapMode mode, long position, long size) |
| throws IOException; |
| |
| /** |
| * Return the size of the file thus far |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| */ |
| public abstract long size() throws IOException; |
| |
| /** |
| * Writes data to the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public final long write(ByteBuffer[] srcs) throws IOException |
| { |
| return write(srcs, 0, srcs.length); |
| } |
| |
| /** |
| * Writes data to the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract int write(ByteBuffer src) throws IOException; |
| |
| /** |
| * Writes data to the channel. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedByInterruptException If another thread interrupts the |
| * current thread while the transfer is in progress, thereby closing both |
| * channels and setting the current thread's interrupt status. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If position is negative. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonWritableChannelException If this channel was not opened for |
| * writing. |
| */ |
| public abstract int write(ByteBuffer srcs, long position) |
| throws IOException; |
| |
| /** |
| * Writes data to the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract long write(ByteBuffer[] srcs, int offset, int length) |
| throws IOException; |
| |
| /** |
| * Reads data from the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract long read(ByteBuffer[] dsts, int offset, int length) |
| throws IOException; |
| |
| /** |
| * Reads data from the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public final long read(ByteBuffer[] dsts) throws IOException |
| { |
| return read(dsts, 0, dsts.length); |
| } |
| |
| /** |
| * Reads data from the channel. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract int read(ByteBuffer dst) throws IOException; |
| |
| /** |
| * Reads data from the channel. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedByInterruptException If another thread interrupts the |
| * current thread while the transfer is in progress, thereby closing both |
| * channels and setting the current thread's interrupt status. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If position is negative. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonReadableChannelException If this channel was not opened for |
| * reading. |
| */ |
| public abstract int read(ByteBuffer dst, long position) |
| throws IOException; |
| |
| /** |
| * Closes the channel. |
| * |
| * This is called from @see close. |
| * |
| * @exception IOException If an I/O error occurs. |
| */ |
| protected abstract void implCloseChannel() throws IOException; |
| |
| /** |
| * msync with the disk |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract void force(boolean metaData) throws IOException; |
| |
| /** |
| * Creates a file lock for the whole associated file. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception FileLockInterruptionException If the invoking thread is |
| * interrupted while blocked in this method. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonReadableChannelException If shared is true and this channel |
| * was not opened for reading. |
| * @exception NonWritableChannelException If shared is false and this channel |
| * was not opened for writing. |
| * @exception OverlappingFileLockException If a lock that overlaps the |
| * requested region is already held by this Java virtual machine, or if |
| * another thread is already blocked in this method and is attempting to lock |
| * an overlapping region. |
| */ |
| public final FileLock lock() throws IOException |
| { |
| return lock(0, Long.MAX_VALUE, false); |
| } |
| |
| /** |
| * Creates a file lock for a region of the associated file. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception FileLockInterruptionException If the invoking thread is |
| * interrupted while blocked in this method. |
| * @exception IllegalArgumentException If the preconditions on the parameters |
| * do not hold. |
| * @exception IOException If an I/O error occurs. |
| * @exception OverlappingFileLockException If a lock that overlaps the |
| * requested region is already held by this Java virtual machine, or if |
| * another thread is already blocked in this method and is attempting to lock |
| * an overlapping region. |
| * @exception NonReadableChannelException If shared is true and this channel |
| * was not opened for reading. |
| * @exception NonWritableChannelException If shared is false and this channel |
| * was not opened for writing. |
| */ |
| public abstract FileLock lock(long position, long size, boolean shared) |
| throws IOException; |
| |
| /** |
| * Tries to aqquire alock on the whole associated file. |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IOException If an I/O error occurs. |
| * @exception OverlappingFileLockException If a lock that overlaps the |
| * requested region is already held by this Java virtual machine, or if |
| * another thread is already blocked in this method and is attempting to lock |
| * an overlapping region. |
| */ |
| public final FileLock tryLock() throws IOException |
| { |
| return tryLock(0, Long.MAX_VALUE, false); |
| } |
| |
| /** |
| * Tries to aqquire a lock on a region of the associated file. |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If the preconditions on the parameters |
| * do not hold. |
| * @exception IOException If an I/O error occurs. |
| * @exception OverlappingFileLockException If a lock that overlaps the |
| * requested region is already held by this Java virtual machine, or if |
| * another thread is already blocked in this method and is attempting to lock |
| * an overlapping region. |
| */ |
| public abstract FileLock tryLock(long position, long size, boolean shared) |
| throws IOException; |
| |
| /** |
| * Returns the current position on the file. |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract long position() throws IOException; |
| |
| /** |
| * Sets the position of the channel on the assoziated file. |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If newPosition is negative. |
| * @exception IOException If an I/O error occurs. |
| */ |
| public abstract FileChannel position(long newPosition) |
| throws IOException; |
| |
| /** |
| * Transfers bytes from this channel's file to the given writable byte |
| * channel. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedByInterruptException If another thread interrupts the |
| * current thread while the transfer is in progress, thereby closing both |
| * channels and setting the current thread's interrupt status. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If the preconditions on the parameters |
| * do not hold. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonReadableChannelException If this channel was not opened for |
| * reading. |
| * @exception NonWritableChannelException If the target channel was not |
| * opened for writing. |
| */ |
| public abstract long transferTo(long position, long count, |
| WritableByteChannel target) |
| throws IOException; |
| |
| /** |
| * Transfers bytes from the given readable channel into this channel. |
| * |
| * @exception AsynchronousCloseException If another thread closes this channel |
| * while the transfer is in progress. |
| * @exception ClosedByInterruptException If another thread interrupts the |
| * current thread while the transfer is in progress, thereby closing both |
| * channels and setting the current thread's interrupt status. |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If the preconditions on the parameters |
| * do not hold. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonReadableChannelException If the source channel was not |
| * opened for reading. |
| * @exception NonWritableChannelException If this channel was not opened for |
| * writing. |
| */ |
| public abstract long transferFrom(ReadableByteChannel src, long position, |
| long count) throws IOException; |
| |
| /** |
| * Truncates the channel's file at <code>size</code>. |
| * |
| * @exception ClosedChannelException If this channel is closed. |
| * @exception IllegalArgumentException If size is negative. |
| * @exception IOException If an I/O error occurs. |
| * @exception NonWritableChannelException If this channel was not opened for |
| * writing. |
| */ |
| public abstract FileChannel truncate(long size) throws IOException; |
| } |