Module de.bernd_michaely.common.io.random

Package de.bernd_michaely.common.io.random

Class RandomAccessDataScope

java.lang.Object

de.bernd_michaely.common.io.random.RandomAccessDataScope

All Implemented Interfaces:

RandomAccessData, AutoCloseable

public class RandomAccessDataScope
extends Object
implements RandomAccessData

Provides a RandomAccessData source for accessing a limited area of an underlying RandomAccessData source.

Since:

2.0

Method Summary

Modifier and Type	Method	Description
void	close()
long	getCurrentOffset()	Returns the current offset within this data.
long	getLength()	Returns the length of the data in bytes.
boolean	isClosed()	Returns true, if the data source was closed before.
void	readBytes(byte[] buffer, int offset, int length)	Reads an array of bytes of the given length from this data source into the given buffer at the given offset.
byte[]	readBytes(int length)	Reads an array of bytes of the given length from this data source.
int	readUnsignedByte()	Reads an unsigned eight bit number from this data.
void	setCurrentOffset(long offset)	Sets the current offset within this data.

Methods inherited from class java.lang.Object

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

Method Detail

close

public void close()
           throws RandomAccessDataException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface RandomAccessData

Throws:

RandomAccessDataException

isClosed

public boolean isClosed()

Description copied from interface: RandomAccessData

Returns true, if the data source was closed before.

Specified by:

isClosed in interface RandomAccessData

Returns:

true, if the data source was closed

getLength

public long getLength()
               throws RandomAccessDataClosedException

Description copied from interface: RandomAccessData

Returns the length of the data in bytes.

Specified by:

getLength in interface RandomAccessData

Returns:

the length of the data in bytes

Throws:

RandomAccessDataClosedException

getCurrentOffset

public long getCurrentOffset()
                      throws RandomAccessDataException

Description copied from interface: RandomAccessData

Returns the current offset within this data.

Specified by:

getCurrentOffset in interface RandomAccessData

Returns:

offset in bytes

Throws:

RandomAccessDataException - if RandomAccessData source is invalid

setCurrentOffset

public void setCurrentOffset(long offset)
                      throws RandomAccessDataException,
                             IllegalArgumentException

Description copied from interface: RandomAccessData

Sets the current offset within this data. The offset may be set beyond the end of the file without throwing an exception. (Reading after that will do so.)

Specified by:

setCurrentOffset in interface RandomAccessData

Parameters:

offset - offset in bytes

Throws:

RandomAccessDataException - if an I/O error occurs

IllegalArgumentException - if the offset given is less than zero

readUnsignedByte

public int readUnsignedByte()
                     throws RandomAccessDataException

Description copied from interface: RandomAccessData

Reads an unsigned eight bit number from this data.

Specified by:

readUnsignedByte in interface RandomAccessData

Returns:

the next byte of this file as an unsigned eight bit number

Throws:

RandomAccessDataException - if an I/O error occurs

RandomAccessEndOfDataException - if the end of data is reached

readBytes

public byte[] readBytes(int length)
                 throws RandomAccessDataException

Description copied from interface: RandomAccessData

Reads an array of bytes of the given length from this data source.

Specified by:

readBytes in interface RandomAccessData

Parameters:

length - the number of bytes to read

Returns:

the bytes read as byte array

Throws:

RandomAccessDataException - if an I/O error occurs

RandomAccessEndOfDataException - if the end of data is reached

readBytes

public void readBytes(byte[] buffer,
                      int offset,
                      int length)
               throws RandomAccessDataException

Description copied from interface: RandomAccessData

Reads an array of bytes of the given length from this data source into the given buffer at the given offset. The caller is responsible to provide a buffer of sufficient size.

Specified by:

readBytes in interface RandomAccessData

Parameters:

buffer - the buffer to write the read data to

offset - starting index to write the data read into the buffer

length - the number of bytes to read

Throws:

RandomAccessDataException - if an I/O error occurs

RandomAccessEndOfDataException - if the end of data is reached

See Also:

RandomAccessData.readBytes(int)