public static int calculateStorageRequirements(int entryCount) 
{
        return (entryCount + _entries_per_block - 1) / _entries_per_block;
}

Calculate how many BATBlocks are needed to hold a specified number of BAT entries.

 public static int calculateXBATStorageRequirements(int entryCount) 
{
        return (entryCount + _entries_per_xbat_block - 1)
               / _entries_per_xbat_block;
}

Calculate how many XBATBlocks are needed to hold a specified number of BAT entries.

 public static BATBlock[] createBATBlocks(int[] entries) 
{
        int        block_count = calculateStorageRequirements(entries.length);
        BATBlock[] blocks      = new BATBlock[ block_count ];
        int        index       = 0;
        int        remaining   = entries.length;
        for (int j = 0; j <  entries.length; j += _entries_per_block)
        {
            blocks[ index++ ] = new BATBlock(entries, j,
                                             (remaining  > _entries_per_block)
                                             ? j + _entries_per_block
                                             : entries.length);
            remaining         -= _entries_per_block;
        }
        return blocks;
}

Create an array of BATBlocks from an array of int block allocation table entries

 public static BATBlock[] createXBATBlocks(int[] entries,
    int startBlock) 
{
        int        block_count =
            calculateXBATStorageRequirements(entries.length);
        BATBlock[] blocks      = new BATBlock[ block_count ];
        int        index       = 0;
        int        remaining   = entries.length;
        if (block_count != 0)
        {
            for (int j = 0; j <  entries.length; j += _entries_per_xbat_block)
            {
                blocks[ index++ ] =
                    new BATBlock(entries, j,
                                 (remaining  > _entries_per_xbat_block)
                                 ? j + _entries_per_xbat_block
                                 : entries.length);
                remaining         -= _entries_per_xbat_block;
            }
            for (index = 0; index <  blocks.length - 1; index++)
            {
                blocks[ index ].setXBATChain(startBlock + index + 1);
            }
            blocks[ index ].setXBATChain(POIFSConstants.END_OF_CHAIN);
        }
        return blocks;
}

Create an array of XBATBlocks from an array of int block allocation table entries

 public static final int entriesPerBlock() 
{
        return _entries_per_block;
}

 public static final int entriesPerXBATBlock() 
{
        return _entries_per_xbat_block;
}

 public static final int getXBATChainOffset() 
{
        return _xbat_chain_offset;
}

  void writeData(OutputStream stream) throws IOException 
{
        doWriteData(stream, _data);
}

Write the block's data to an OutputStream