HSSFWorkbook workbook = new HSSFWorkbook();
this.dateCellStyle = createDateCellStyle(workbook);
int index = 0;
ITableIterator iterator = dataSet.iterator();
while(iterator.next())
{
// create the table i.e. sheet
ITable table = iterator.getTable();
ITableMetaData metaData = table.getTableMetaData();
HSSFSheet sheet = workbook.createSheet(metaData.getTableName());
// write table metadata i.e. first row in sheet
workbook.setSheetName(index, metaData.getTableName());