org.eclipse.rdf4j.common.io

Class NioFile

java.lang.Object

org.eclipse.rdf4j.common.io.NioFile

All Implemented Interfaces:

Closeable, AutoCloseable

public final class NioFile
extends Object
implements Closeable

File wrapper that protects against concurrent file closing events due to e.g. thread interrupts. In case the file channel that is used by this class is closed due to such an event, it will try to reopen the channel. The thread that causes the ClosedByInterruptException is not protected, assuming the interrupt is intended to end the thread's operation.

Author:

Arjohn Kampman

Constructor Summary

Constructors

Constructor and Description
NioFile(File file) Constructor Opens a file in read/write mode, creating a new one if the file doesn't exist.
NioFile(File file, String mode) Constructor Opens a file in a specific mode, creating a new one if the file doesn't exist.

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	delete() Close any open channels and then deletes the file.
void	force(boolean metaData) Performs a protected FileChannel.force(boolean) call.
File	getFile()
boolean	isClosed() Check if a file was closed explicitly.
int	read(ByteBuffer buf, long offset) Performs a protected FileChannel.read(ByteBuffer, long) call.
byte	readByte(long offset) Read single byte from channel starting at offset.
byte[]	readBytes(long offset, int length) Read a byte array of a specifi length from channel starting at offset.
int	readInt(long offset) Read integer value from channel starting at offset.
long	readLong(long offset) Read long value from channel starting at offset.
long	size() Performs a protected FileChannel.size() call.
long	transferTo(long position, long count, WritableByteChannel target) Performs a protected FileChannel.transferTo(long, long, WritableByteChannel) call.
void	truncate(long size) Performs a protected FileChannel.truncate(long) call.
int	write(ByteBuffer buf, long offset) Performs a protected FileChannel.write(ByteBuffer, long) call.
void	writeByte(byte value, long offset) Write single byte to channel starting at offset.
void	writeBytes(byte[] value, long offset) Write byte array to channel starting at offset.
void	writeInt(int value, long offset) Write integer value to channel starting at offset.
void	writeLong(long value, long offset) Write long value to channel starting at offset.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NioFile

public NioFile(File file)
        throws IOException

Constructor Opens a file in read/write mode, creating a new one if the file doesn't exist.

Parameters:

file -

Throws:

IOException

NioFile

public NioFile(File file,
               String mode)
        throws IOException

Constructor Opens a file in a specific mode, creating a new one if the file doesn't exist.

Parameters:

file - file

mode - file mode

Throws:

IOException

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

isClosed

public boolean isClosed()

Check if a file was closed explicitly.

Returns:

true if it was closed explicitly

getFile

public File getFile()

delete

public boolean delete()
               throws IOException

Close any open channels and then deletes the file.

Returns:

true if the file has been deleted successfully, false otherwise.

Throws:

IOException - If there was a problem closing the open file channel.

force

public void force(boolean metaData)
           throws IOException

Performs a protected FileChannel.force(boolean) call.

Parameters:

metaData -

Throws:

IOException

truncate

public void truncate(long size)
              throws IOException

Performs a protected FileChannel.truncate(long) call.

Parameters:

size -

Throws:

IOException

size

public long size()
          throws IOException

Performs a protected FileChannel.size() call.

Returns:

size of the file

Throws:

IOException

transferTo

public long transferTo(long position,
                       long count,
                       WritableByteChannel target)
                throws IOException

Performs a protected FileChannel.transferTo(long, long, WritableByteChannel) call.

Parameters:

position - position within the file

count - number of bytes to transfer

target - target channel

Returns:

number of bytes transferred

Throws:

IOException

write

public int write(ByteBuffer buf,
                 long offset)
          throws IOException

Performs a protected FileChannel.write(ByteBuffer, long) call.

Parameters:

buf - buffer

offset - non-negative offset

Returns:

number of bytes written

Throws:

IOException

read

public int read(ByteBuffer buf,
                long offset)
         throws IOException

Performs a protected FileChannel.read(ByteBuffer, long) call.

Parameters:

buf - buffer to read

offset - non-negative offset

Returns:

number of bytes read

Throws:

IOException

writeBytes

public void writeBytes(byte[] value,
                       long offset)
                throws IOException

Write byte array to channel starting at offset.

Parameters:

value - byte array to write

offset - non-negative offset

Throws:

IOException

readBytes

public byte[] readBytes(long offset,
                        int length)
                 throws IOException

Read a byte array of a specifi length from channel starting at offset.

Parameters:

offset -

length -

Returns:

Throws:

IOException

writeByte

public void writeByte(byte value,
                      long offset)
               throws IOException

Write single byte to channel starting at offset.

Parameters:

value - value to write

offset - non-negative offset

Throws:

IOException

readByte

public byte readByte(long offset)
              throws IOException

Read single byte from channel starting at offset.

Parameters:

offset - non-negative offset

Returns:

byte

Throws:

IOException

writeLong

public void writeLong(long value,
                      long offset)
               throws IOException

Write long value to channel starting at offset.

Parameters:

value - value to write

offset - non-negative offset

Throws:

IOException

readLong

public long readLong(long offset)
              throws IOException

Read long value from channel starting at offset.

Parameters:

offset - non-negative offset

Returns:

long

Throws:

IOException

writeInt

public void writeInt(int value,
                     long offset)
              throws IOException

Write integer value to channel starting at offset.

Parameters:

value - value to write

offset - non-negative offset

Throws:

IOException

readInt

public int readInt(long offset)
            throws IOException

Read integer value from channel starting at offset.

Parameters:

offset - non-negative offset

Returns:

integer

Throws:

IOException