org.apache.pdfbox.io

Class RandomAccessReadWrapper

java.lang.Object

org.apache.pdfbox.io.RandomAccessReadWrapper

All Implemented Interfaces:

Closeable, AutoCloseable, RandomAccessRead, SequentialRead

public class RandomAccessReadWrapper
extends Object
implements RandomAccessRead

A read only wrapper for a RandomAccessRead instance.

Constructor Summary

Constructors

Constructor and Description
RandomAccessReadWrapper(RandomAccessRead input, long offset, long length) Create a read only wrapper for a RandomAccessRead instance.

Method Summary

Modifier and Type	Method and Description
int	available() Returns an estimate of the number of bytes that can be read.
void	close()
long	getPosition() Returns offset in file at which next byte would be read.
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 off, int len) 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 newOffset) Seeks to new position.

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomAccessReadWrapper

public RandomAccessReadWrapper(RandomAccessRead input,
                               long offset,
                               long length)
                        throws IOException

Create a read only wrapper for a RandomAccessRead instance.

Parameters:

input - the RandomAccessRead instance to be read.

offset - offset to start reading at.

length - the total length of data to be read.

Throws:

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

Method Detail

getPosition

public long getPosition()
                 throws IOException

Returns offset in file at which next byte would be read.

Specified by:

getPosition in interface RandomAccessRead

Returns:

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

Throws:

IOException

seek

public void seek(long newOffset)
          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:

newOffset - the position to seek to.

Throws:

IOException - if something went wrong.

read

public int read()
         throws IOException

Description copied from interface: SequentialRead

Read a single byte of data.

Specified by:

read in interface SequentialRead

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)
         throws IOException

Description copied from interface: SequentialRead

Read a buffer of data.

Specified by:

read in interface SequentialRead

Parameters:

b - The buffer to write the data to.

Returns:

The number of bytes that were actually read.

Throws:

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

read

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

Description copied from interface: SequentialRead

Read a buffer of data.

Specified by:

read in interface SequentialRead

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.

available

public int available()
              throws 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:

IOException - if this random access has been closed

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 stream has been closed.

Specified by:

isClosed in interface RandomAccessRead

peek

public int peek()
         throws 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:

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

rewind

public void rewind(int bytes)
            throws 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:

IOException - If there is an error while seeking

readFully

public byte[] readFully(int length)
                 throws 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:

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

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.