com.itextpdf.io.source

Class WindowRandomAccessSource

java.lang.Object

com.itextpdf.io.source.WindowRandomAccessSource

All Implemented Interfaces:

IRandomAccessSource, Serializable

public class WindowRandomAccessSource
extends Object
implements IRandomAccessSource, Serializable

A RandomAccessSource that wraps another RandomAccessSource and provides a window of it at a specific offset and over a specific length. Position 0 becomes the offset position in the underlying source.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
WindowRandomAccessSource(IRandomAccessSource source, long offset) Constructs a new OffsetRandomAccessSource that extends to the end of the underlying source
WindowRandomAccessSource(IRandomAccessSource source, long offset, long length) Constructs a new OffsetRandomAccessSource with an explicit length

Method Summary

Modifier and Type	Method and Description
void	close() Closes this source.
int	get(long position) Gets a byte at the specified position
int	get(long position, byte[] bytes, int off, int len) Read an array of bytes of specified length from the specified position of source to the buffer applying the offset.
long	length() Gets the length of the source

Methods inherited from class java.lang.Object

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

Constructor Detail

WindowRandomAccessSource

public WindowRandomAccessSource(IRandomAccessSource source,
                                long offset)

Constructs a new OffsetRandomAccessSource that extends to the end of the underlying source

Parameters:

source - the source

offset - the amount of the offset to use

WindowRandomAccessSource

public WindowRandomAccessSource(IRandomAccessSource source,
                                long offset,
                                long length)

Constructs a new OffsetRandomAccessSource with an explicit length

Parameters:

source - the source

offset - the amount of the offset to use

length - the number of bytes to be included in this RAS

Method Detail

get

public int get(long position)
        throws IOException

Gets a byte at the specified position Note that the position will be adjusted to read from the corrected location in the underlying source

Specified by:

get in interface IRandomAccessSource

Parameters:

position - byte position

Returns:

the byte, or -1 if EOF is reached

Throws:

IOException - in case of any reading error.

get

public int get(long position,
               byte[] bytes,
               int off,
               int len)
        throws IOException

Read an array of bytes of specified length from the specified position of source to the buffer applying the offset. If the number of bytes requested cannot be read, all the possible bytes will be read to the buffer, and the number of actually read bytes will be returned. Note that the position will be adjusted to read from the corrected location in the underlying source

Specified by:

get in interface IRandomAccessSource

Parameters:

position - the position in the RandomAccessSource to read from

bytes - output buffer

off - offset into the output buffer where results will be placed

len - the number of bytes to read

Returns:

the number of bytes actually read, or -1 if the file is at EOF

Throws:

IOException - in case of any I/O error.

length

public long length()

Gets the length of the source Note that the length will be adjusted to read from the corrected location in the underlying source

Specified by:

length in interface IRandomAccessSource

Returns:

the length of this source

close

public void close()
           throws IOException

Closes this source. The underlying data structure or source (if any) will also be closed

Specified by:

close in interface IRandomAccessSource

Throws:

IOException