/* FileDescriptor.java -- Opaque file handle class
|
/* FileDescriptor.java -- Opaque file handle class
|
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004
|
Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004
|
Free Software Foundation, Inc.
|
Free Software Foundation, Inc.
|
|
|
This file is part of GNU Classpath.
|
This file is part of GNU Classpath.
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
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
|
it under the terms of the GNU General Public License as published by
|
the Free Software Foundation; either version 2, or (at your option)
|
the Free Software Foundation; either version 2, or (at your option)
|
any later version.
|
any later version.
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
GNU Classpath is distributed in the hope that it will be useful, but
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
General Public License for more details.
|
General Public License for more details.
|
|
|
You should have received a copy of the GNU General Public License
|
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
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
02110-1301 USA.
|
02110-1301 USA.
|
|
|
Linking this library statically or dynamically with other modules is
|
Linking this library statically or dynamically with other modules is
|
making a combined work based on this library. Thus, the terms and
|
making a combined work based on this library. Thus, the terms and
|
conditions of the GNU General Public License cover the whole
|
conditions of the GNU General Public License cover the whole
|
combination.
|
combination.
|
|
|
As a special exception, the copyright holders of this library give you
|
As a special exception, the copyright holders of this library give you
|
permission to link this library with independent modules to produce an
|
permission to link this library with independent modules to produce an
|
executable, regardless of the license terms of these independent
|
executable, regardless of the license terms of these independent
|
modules, and to copy and distribute the resulting executable under
|
modules, and to copy and distribute the resulting executable under
|
terms of your choice, provided that you also meet, for each linked
|
terms of your choice, provided that you also meet, for each linked
|
independent module, the terms and conditions of the license of that
|
independent module, the terms and conditions of the license of that
|
module. An independent module is a module which is not derived from
|
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
|
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
|
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
|
obligated to do so. If you do not wish to do so, delete this
|
exception statement from your version. */
|
exception statement from your version. */
|
|
|
|
|
package java.io;
|
package java.io;
|
|
|
import gnu.java.nio.FileChannelImpl;
|
import gnu.java.nio.FileChannelImpl;
|
|
|
import java.nio.channels.ByteChannel;
|
import java.nio.channels.ByteChannel;
|
import java.nio.channels.FileChannel;
|
import java.nio.channels.FileChannel;
|
|
|
/**
|
/**
|
* This class represents an opaque file handle as a Java class. It should
|
* This class represents an opaque file handle as a Java class. It should
|
* be used only to pass to other methods that expect an object of this
|
* be used only to pass to other methods that expect an object of this
|
* type. No system specific information can be obtained from this object.
|
* type. No system specific information can be obtained from this object.
|
*
|
*
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
* @author Tom Tromey (tromey@cygnus.com)
|
* @author Tom Tromey (tromey@cygnus.com)
|
* @date September 24, 1998
|
* @date September 24, 1998
|
*/
|
*/
|
public final class FileDescriptor
|
public final class FileDescriptor
|
{
|
{
|
/**
|
/**
|
* A <code>FileDescriptor</code> representing the system standard input
|
* A <code>FileDescriptor</code> representing the system standard input
|
* stream. This will usually be accessed through the
|
* stream. This will usually be accessed through the
|
* <code>System.in</code>variable.
|
* <code>System.in</code>variable.
|
*/
|
*/
|
public static final FileDescriptor in
|
public static final FileDescriptor in
|
= new FileDescriptor (FileChannelImpl.in);
|
= new FileDescriptor (FileChannelImpl.in);
|
|
|
/**
|
/**
|
* A <code>FileDescriptor</code> representing the system standard output
|
* A <code>FileDescriptor</code> representing the system standard output
|
* stream. This will usually be accessed through the
|
* stream. This will usually be accessed through the
|
* <code>System.out</code>variable.
|
* <code>System.out</code>variable.
|
*/
|
*/
|
public static final FileDescriptor out
|
public static final FileDescriptor out
|
= new FileDescriptor (FileChannelImpl.out);
|
= new FileDescriptor (FileChannelImpl.out);
|
|
|
/**
|
/**
|
* A <code>FileDescriptor</code> representing the system standard error
|
* A <code>FileDescriptor</code> representing the system standard error
|
* stream. This will usually be accessed through the
|
* stream. This will usually be accessed through the
|
* <code>System.err</code>variable.
|
* <code>System.err</code>variable.
|
*/
|
*/
|
public static final FileDescriptor err
|
public static final FileDescriptor err
|
= new FileDescriptor (FileChannelImpl.err);
|
= new FileDescriptor (FileChannelImpl.err);
|
|
|
final ByteChannel channel;
|
final ByteChannel channel;
|
|
|
/**
|
/**
|
* This method is used to initialize an invalid FileDescriptor object.
|
* This method is used to initialize an invalid FileDescriptor object.
|
*/
|
*/
|
public FileDescriptor()
|
public FileDescriptor()
|
{
|
{
|
channel = null;
|
channel = null;
|
}
|
}
|
|
|
/**
|
/**
|
* This method is used to initialize a FileDescriptor object.
|
* This method is used to initialize a FileDescriptor object.
|
*/
|
*/
|
FileDescriptor(ByteChannel channel)
|
FileDescriptor(ByteChannel channel)
|
{
|
{
|
this.channel = channel;
|
this.channel = channel;
|
}
|
}
|
|
|
|
|
/**
|
/**
|
* This method forces all data that has not yet been physically written to
|
* This method forces all data that has not yet been physically written to
|
* the underlying storage medium associated with this
|
* the underlying storage medium associated with this
|
* <code>FileDescriptor</code>
|
* <code>FileDescriptor</code>
|
* to be written out. This method will not return until all data has
|
* to be written out. This method will not return until all data has
|
* been fully written to the underlying device. If the device does not
|
* been fully written to the underlying device. If the device does not
|
* support this functionality or if an error occurs, then an exception
|
* support this functionality or if an error occurs, then an exception
|
* will be thrown.
|
* will be thrown.
|
*/
|
*/
|
public void sync () throws SyncFailedException
|
public void sync () throws SyncFailedException
|
{
|
{
|
if (channel instanceof FileChannel)
|
if (channel instanceof FileChannel)
|
{
|
{
|
try
|
try
|
{
|
{
|
((FileChannel) channel).force(true);
|
((FileChannel) channel).force(true);
|
}
|
}
|
catch (IOException ex)
|
catch (IOException ex)
|
{
|
{
|
if (ex instanceof SyncFailedException)
|
if (ex instanceof SyncFailedException)
|
throw (SyncFailedException) ex;
|
throw (SyncFailedException) ex;
|
else
|
else
|
throw new SyncFailedException(ex.toString());
|
throw new SyncFailedException(ex.toString());
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
/**
|
/**
|
* This methods tests whether or not this object represents a valid open
|
* This methods tests whether or not this object represents a valid open
|
* native file handle.
|
* native file handle.
|
*
|
*
|
* @return <code>true</code> if this object represents a valid
|
* @return <code>true</code> if this object represents a valid
|
* native file handle, <code>false</code> otherwise
|
* native file handle, <code>false</code> otherwise
|
*/
|
*/
|
public boolean valid ()
|
public boolean valid ()
|
{
|
{
|
ByteChannel c = channel;
|
ByteChannel c = channel;
|
return (c != null) && (c.isOpen());
|
return (c != null) && (c.isOpen());
|
}
|
}
|
}
|
}
|
|
|
