ucar.nc2.iosp.bufr
Class BitReader

java.lang.Object
  ucar.nc2.iosp.bufr.BitReader

public class BitReader
extends java.lang.Object

Helper for reading data that has been bit packed.

Since:

Apr 7, 2008

Author:

caron

Constructor Summary

BitReader(RandomAccessFile raf, long startPos)
Constructor

Method Summary

long	bits2UInt(int nb) Read the next nb bits and return an Unsigned Long .
long	getPos()
static void	main(java.lang.String[] args)
void	setBitOffset(int bitOffset) Position file at bitOffset from startPos

Methods inherited from class java.lang.Object

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

Constructor Detail

BitReader

public BitReader(RandomAccessFile raf,
                 long startPos)
          throws java.io.IOException

Constructor

Parameters:

raf - the RandomAccessFile

startPos - points to start of data in data section, in bytes

Throws:

java.io.IOException - on read error

Method Detail

setBitOffset

public void setBitOffset(int bitOffset)
                  throws java.io.IOException

Position file at bitOffset from startPos

Parameters:

bitOffset - bit offset from starting position

Throws:

java.io.IOException - on io error

bits2UInt

public long bits2UInt(int nb)
               throws java.io.IOException

Read the next nb bits and return an Unsigned Long .

Parameters:

nb - the number of bits to convert to int, must be <= 64.

Returns:

result

Throws:

java.io.IOException - on read error

getPos

public long getPos()
            throws java.io.IOException

Throws:

java.io.IOException

main

public static void main(java.lang.String[] args)
                 throws java.io.IOException

Throws:

java.io.IOException