Package org.apache.pdfbox.io

Class RandomAccessFile

java.lang.Object

org.apache.pdfbox.io.RandomAccessFile

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, RandomAccess, RandomAccessRead, RandomAccessWrite

public class RandomAccessFile
extends java.lang.Object
implements RandomAccess

A RandomAccess implementation which allows data to be stored in a scratch file on the disk to reduce memory consumption.

Author:

Ben Litchfield

Constructor Summary

Constructors

Constructor	Description
RandomAccessFile(java.io.File file, java.lang.String mode)	Constructor.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns an estimate of the number of bytes that can be read.
void	clear()	Clears all data of the buffer.
void	close()
long	getPosition()	Returns offset of next byte to be returned by a read method.
boolean	isClosed()	Returns true if this stream 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	peek()	This will peek at the next byte.
int	read()	Read a single byte of data.
int	read(byte[] b)	Read a buffer of data.
int	read(byte[] b, int offset, int length)	Read a buffer of data.
byte[]	readFully(int length)	Reads a given number of bytes.
void	rewind(int bytes)	Seek backwards the given number of bytes.
void	seek(long position)	Seek to a position in the data.
void	write(byte[] b)	Write a buffer of data to the stream.
void	write(byte[] b, int offset, int length)	Write a buffer of data to the stream.
void	write(int b)	Write a byte to the stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomAccessFile

public RandomAccessFile(java.io.File file,
                        java.lang.String mode)
                 throws java.io.FileNotFoundException

Constructor.

Parameters:

file - The file to write the data to.

mode - The writing mode.

Throws:

java.io.FileNotFoundException - If the file cannot be created.

Method Detail

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

clear

public void clear()
           throws java.io.IOException

Description copied from interface: RandomAccessWrite

Clears all data of the buffer.

Specified by:

clear in interface RandomAccessWrite

Throws:

java.io.IOException

seek

public void seek(long position)
          throws java.io.IOException

Description copied from interface: RandomAccessRead

Seek to a position in the data.

Specified by:

seek in interface RandomAccessRead

Parameters:

position - The position to seek to.

Throws:

java.io.IOException - If there is an error while seeking.

getPosition

public long getPosition()
                 throws java.io.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:

java.io.IOException

read

public int read()
         throws java.io.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:

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

read

public int read(byte[] b)
         throws java.io.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.

Returns:

The number of bytes that were actually read.

Throws:

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

read

public int read(byte[] b,
                int offset,
                int length)
         throws java.io.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.

offset - Offset into the buffer to start writing.

length - The amount of data to attempt to read.

Returns:

The number of bytes that were actually read.

Throws:

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

length

public long length()
            throws java.io.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:

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

isClosed

public boolean isClosed()

Description copied from interface: RandomAccessRead

Returns true if this stream has been closed.

Specified by:

isClosed in interface RandomAccessRead

write

public void write(byte[] b,
                  int offset,
                  int length)
           throws java.io.IOException

Description copied from interface: RandomAccessWrite

Write a buffer of data to the stream.

Specified by:

write in interface RandomAccessWrite

Parameters:

b - The buffer to get the data from.

offset - An offset into the buffer to get the data from.

length - The length of data to write.

Throws:

java.io.IOException - If there is an error while writing the data.

write

public void write(byte[] b)
           throws java.io.IOException

Description copied from interface: RandomAccessWrite

Write a buffer of data to the stream.

Specified by:

write in interface RandomAccessWrite

Parameters:

b - The buffer to get the data from.

Throws:

java.io.IOException - If there is an error while writing the data.

write

public void write(int b)
           throws java.io.IOException

Description copied from interface: RandomAccessWrite

Write a byte to the stream.

Specified by:

write in interface RandomAccessWrite

Parameters:

b - The byte to write.

Throws:

java.io.IOException - If there is an IO error while writing.

peek

public int peek()
         throws java.io.IOException

Description copied from interface: RandomAccessRead

This will peek at the next byte.

Specified by:

peek in interface RandomAccessRead

Returns:

The next byte on the stream, leaving it as available to read.

Throws:

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

rewind

public void rewind(int bytes)
            throws java.io.IOException

Description copied from interface: RandomAccessRead

Seek backwards the given number of bytes.

Specified by:

rewind in interface RandomAccessRead

Parameters:

bytes - the number of bytes to be seeked backwards

Throws:

java.io.IOException - If there is an error while seeking

readFully

public byte[] readFully(int length)
                 throws java.io.IOException

Description copied from interface: RandomAccessRead

Reads a given number of bytes.

Specified by:

readFully in interface RandomAccessRead

Parameters:

length - the number of bytes to be read

Returns:

a byte array containing the bytes just read

Throws:

java.io.IOException - if an I/O error occurs while reading data

isEOF

public boolean isEOF()
              throws java.io.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:

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

available

public int available()
              throws java.io.IOException

Description copied from interface: RandomAccessRead

Returns an estimate of the number of bytes that can be read.

Specified by:

available in interface RandomAccessRead

Returns:

the number of bytes that can be read

Throws:

java.io.IOException - if this random access has been closed