au.com.prunge.jgenfile.channels
Interface RandomAccessChannel

All Superinterfaces:

Channel

All Known Subinterfaces:

RandomAccessByteChannel, RandomAccessReadableByteChannel, RandomAccessWritableByteChannel

All Known Implementing Classes:

RandomAccessFileChannel

public interface RandomAccessChannel

extends Channel

Interface for a channel that supports random access to its data. In other words, the channel has a position and its position may be modified.

Version:

1.0

Author:

Peter Runge

Method Summary

long	position() Returns the channel's position.
RandomAccessChannel	position(long newPosition) Sets this channel's position.
long	size() Returns the size of this channel.

Methods inherited from interface java.nio.channels.Channel

close, isOpen

Method Detail

position

public long position()
              throws ClosedChannelException,
                     IOException

Returns the channel's position.

Returns:

This channel's position, a non-negative integer counting the number of bytes from the beginning of the channel to the current position.

Throws:

ClosedChannelException - if the channel was closed.

IOException - if an I/O error occurs.

position

public RandomAccessChannel position(long newPosition)
                             throws IOException,
                                    ClosedChannelException,
                                    IllegalArgumentException

Sets this channel's position.

Setting the position to a value that is greater than the channel's current size is legal but does not change its size. A later attempt to read bytes at such a position will immediately return an end-of-file indication. A later attempt to write bytes at such a position will cause the channel to be grown to accomodate the new bytes; the values of any bytes between the previous end-of-file and the newly-written bytes are unspecified.

Parameters:

newPosition - The new position, a non-negative integer counting the number of bytes from the beginning of the channel.

Returns:

this channel.

Throws:

IllegalArgumentException - If the new position is negative.

ClosedChannelException - if the channel was closed.

IOException - if an I/O error occurs.

size

public long size()
          throws IOException,
                 ClosedChannelException

Returns the size of this channel.

Returns:

the size of this channel in bytes.

Throws:

ClosedChannelException - if the channel was closed.

IOException - if an I/O error occurs.