nio/channels/SeekableByteChannel.java

32  * A byte channel that maintains a current <i>position</i> and allows the
33  * position to be changed.
37  * written. The current position can be {@link #position() <i>queried</i>} and
38  * {@link #position(long) <i>modified</i>}. The channel also provides access to
43  * <p> The {@link #position(long) position} and {@link #truncate truncate} methods
59      * <p> Bytes are read starting at this channel's current position, and
60      * then the position is updated with the number of bytes actually read.
70      * <p> Bytes are written starting at this channel's current position, unless
73      * which case the position is first advanced to the end. The entity to which
75      * written bytes, and then the position is updated with the number of bytes
83      * Returns this channel's position.
85      * @return  This channel's position,
87      *          from the beginning of the entity to the current position
94     long position() throws IOException;
97      * Sets this channel's position.
99      * <p> Setting the position to a value that is greater than the current size
101      * read bytes at such a position will immediately return an end-of-file
102      * indication.  A later attempt to write bytes at such a position will cause
107      * <p> Setting the channel's position is not recommended when connected to
110      * append, the position is first advanced to the end before writing.
113      *         The new position, a non-negative integer counting
121      *          If the new position is negative
125     SeekableByteChannel position(long newPosition) throws IOException;
146      * In either case, if the current position is greater than the given size