Package com.itextpdf.io.source

Class FileChannelRandomAccessSource

java.lang.Object

com.itextpdf.io.source.FileChannelRandomAccessSource

All Implemented Interfaces:

IRandomAccessSource

public class FileChannelRandomAccessSource
extends java.lang.Object
implements IRandomAccessSource

A RandomAccessSource that is based on an underlying FileChannel. The entire channel will be mapped into memory for efficient reads.

Field Summary

Fields

Modifier and Type	Field	Description
private java.nio.channels.FileChannel	channel	The channel this source is based on
private MappedChannelRandomAccessSource	source	Tracks the actual mapping

Constructor Summary

Constructors

Constructor	Description
FileChannelRandomAccessSource(java.nio.channels.FileChannel channel)	Constructs a new FileChannelRandomAccessSource based on the specified FileChannel.

Method Summary

Modifier and Type	Method	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

Field Detail

channel

private final java.nio.channels.FileChannel channel

The channel this source is based on

source

private final MappedChannelRandomAccessSource source

Tracks the actual mapping

Constructor Detail

FileChannelRandomAccessSource

public FileChannelRandomAccessSource(java.nio.channels.FileChannel channel)
                              throws java.io.IOException

Constructs a new FileChannelRandomAccessSource based on the specified FileChannel. The entire source channel will be mapped into memory.

Parameters:

channel - the channel to use as the backing store

Throws:

java.io.IOException - if the channel cannot be opened or mapped

Method Detail

close

public void close()
           throws java.io.IOException

Closes this source. The underlying data structure or source (if any) will also be closed Cleans the mapped byte buffers and closes the channel

Specified by:

close in interface IRandomAccessSource

Throws:

java.io.IOException - in case of any reading error.

get

public int get(long position)
        throws java.io.IOException

Gets a byte at the specified position

Specified by:

get in interface IRandomAccessSource

Parameters:

position - byte position

Returns:

the byte, or -1 if EOF is reached

Throws:

java.io.IOException - in case of any reading error.

get

public int get(long position,
               byte[] bytes,
               int off,
               int len)
        throws java.io.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.

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:

java.io.IOException - in case of any I/O error.

length

public long length()

Gets the length of the source

Specified by:

length in interface IRandomAccessSource

Returns:

the length of this source