public HeaderBlockReader(InputStream stream) throws IOException 
{
                            
    	// At this point, we don't know how big our
    	//  block sizes are
    	// So, read the first 32 bytes to check, then
    	//  read the rest of the block
    	byte[] blockStart = new byte[32];
    	int bsCount = IOUtils.readFully(stream, blockStart);
    	if(bsCount != 32) {
    		alertShortRead(bsCount);
    	}
    	// Figure out our block size
    	if(blockStart[30] == 12) {
    		bigBlockSize = POIFSConstants.LARGER_BIG_BLOCK_SIZE;
    	}
        _data = new byte[ bigBlockSize ];
        System.arraycopy(blockStart, 0, _data, 0, blockStart.length);
    	// Now we can read the rest of our header
        int byte_count = IOUtils.readFully(stream, _data, blockStart.length, _data.length - blockStart.length);
        if (byte_count+bsCount != bigBlockSize) {
    		alertShortRead(byte_count);
        }
        // verify signature
        LongField signature = new LongField(_signature_offset, _data);
        if (signature.get() != _signature)
        {
			// Is it one of the usual suspects?
        	byte[] OOXML_FILE_HEADER = POIFSConstants.OOXML_FILE_HEADER;
			if(_data[0] == OOXML_FILE_HEADER[0] && 
					_data[1] == OOXML_FILE_HEADER[1] && 
					_data[2] == OOXML_FILE_HEADER[2] &&
					_data[3] == OOXML_FILE_HEADER[3]) {
				throw new OfficeXmlFileException("The supplied data appears to be in the Office 2007+ XML. POI only supports OLE2 Office documents");
			}
			// Give a generic error
            throw new IOException("Invalid header signature; read "
                                  + signature.get() + ", expected "
                                  + _signature);
        }
        _bat_count      = new IntegerField(_bat_count_offset, _data);
        _property_start = new IntegerField(_property_start_offset, _data);
        _sbat_start     = new IntegerField(_sbat_start_offset, _data);
        _xbat_start     = new IntegerField(_xbat_start_offset, _data);
        _xbat_count     = new IntegerField(_xbat_count_offset, _data);
}

create a new HeaderBlockReader from an InputStream

Parameters:

stream - the source InputStream

Throws:

IOException - on errors or bad data

exception: IOException - on errors or bad data

 public int[] getBATArray() 
{
        int[] result = new int[ _max_bats_in_header ];
        int   offset = _bat_array_offset;
        for (int j = 0; j <  _max_bats_in_header; j++)
        {
            result[ j ] = LittleEndian.getInt(_data, offset);
            offset      += LittleEndianConsts.INT_SIZE;
        }
        return result;
}

 public int getBATCount() 
{
        return _bat_count.get();
}

 public int getBigBlockSize() 
{
    	return bigBlockSize;
}

 public int getPropertyStart() 
{
        return _property_start.get();
}

get start of Property Table

 public int getSBATStart() 
{
        return _sbat_start.get();
}

 public int getXBATCount() 
{
        return _xbat_count.get();
}

 public int getXBATIndex() 
{
        return _xbat_start.get();
}