org.apache.pdfbox.io

Class RandomAccessReadBufferedFile

java.lang.Object

org.apache.pdfbox.io.RandomAccessReadBufferedFile

All Implemented Interfaces:

Closeable, AutoCloseable, RandomAccessRead

public class RandomAccessReadBufferedFile
extends Object
implements RandomAccessRead

Provides random access to portions of a file combined with buffered reading of content. Start of next bytes to read can be set via seek method. File is accessed via FileChannel and is read in ByteBuffer chunks which are cached.

Author:

Timo Boehme

Constructor Summary

Constructors

Constructor and Description
RandomAccessReadBufferedFile(File file) Create a random access buffered file instance for the given file.
RandomAccessReadBufferedFile(String filename) Create a random access buffered file instance for the file with the given name.

Method Summary

Modifier and Type	Method and Description
void	close()
RandomAccessReadView	createView(long startPosition, long streamLength) Creates a random access read view starting at the given position with the given length.
long	getPosition() Returns offset of next byte to be returned by a read method.
boolean	isClosed() Returns true if this source has been closed.
boolean	isEOF() A simple test to see if we are at the end of the data.
long	length() The total number of bytes that are available.
int	read() Read a single byte of data.
int	read(byte[] b, int off, int len) Read a buffer of data.
void	seek(long position) Seeks to new position.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.pdfbox.io.RandomAccessRead

available, peek, read, rewind, skip

Constructor Detail

RandomAccessReadBufferedFile

public RandomAccessReadBufferedFile(String filename)
                             throws IOException

Create a random access buffered file instance for the file with the given name.

Parameters:

filename - the filename of the file to be read.

Throws:

IOException - if something went wrong while accessing the given file.

RandomAccessReadBufferedFile

public RandomAccessReadBufferedFile(File file)
                             throws IOException

Create a random access buffered file instance for the given file.

Parameters:

file - the file to be read.

Throws:

IOException - if something went wrong while accessing the given file.

Method Detail

getPosition

public long getPosition()
                 throws IOException

Description copied from interface: RandomAccessRead

Returns offset of next byte to be returned by a read method.

Specified by:

getPosition in interface RandomAccessRead

Returns:

offset of next byte which will be returned with next RandomAccessRead.read() (if no more bytes are left it returns a value >= length of source)

Throws:

IOException - If there was an error while getting the current position

seek

public void seek(long position)
          throws IOException

Seeks to new position. If new position is outside of current page the new page is either taken from cache or read from file and added to cache.

Specified by:

seek in interface RandomAccessRead

Parameters:

position - the position to seek to.

Throws:

IOException - if something went wrong.

read

public int read()
         throws IOException

Description copied from interface: RandomAccessRead

Read a single byte of data.

Specified by:

read in interface RandomAccessRead

Returns:

The byte of data that is being read.

Throws:

IOException - If there is an error while reading the data.

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Description copied from interface: RandomAccessRead

Read a buffer of data.

Specified by:

read in interface RandomAccessRead

Parameters:

b - The buffer to write the data to.

off - Offset into the buffer to start writing.

len - The amount of data to attempt to read.

Returns:

The number of bytes that were actually read.

Throws:

IOException - If there was an error while reading the data.

length

public long length()
            throws IOException

Description copied from interface: RandomAccessRead

The total number of bytes that are available.

Specified by:

length in interface RandomAccessRead

Returns:

The number of bytes available.

Throws:

IOException - If there is an IO error while determining the length of the data stream.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

isClosed

public boolean isClosed()

Description copied from interface: RandomAccessRead

Returns true if this source has been closed.

Specified by:

isClosed in interface RandomAccessRead

Returns:

true if the source has been closed

isEOF

public boolean isEOF()
              throws IOException

Description copied from interface: RandomAccessRead

A simple test to see if we are at the end of the data.

Specified by:

isEOF in interface RandomAccessRead

Returns:

true if we are at the end of the data.

Throws:

IOException - If there is an error reading the next byte.

createView

public RandomAccessReadView createView(long startPosition,
                                       long streamLength)
                                throws IOException

Description copied from interface: RandomAccessRead

Creates a random access read view starting at the given position with the given length.

Specified by:

createView in interface RandomAccessRead

Parameters:

startPosition - start position within the underlying random access read

streamLength - stream length

Returns:

the random access read view

Throws:

IOException - if something went wrong when creating the view for the RandomAccessRead