// Get the workbook for further references
_workbook = new HSSFWorkbook(poifs);
// get the Workbook (excel part) stream in a InputStream
din = poifs.createDocumentInputStream( WORKBOOK );
HSSFRequest req = new HSSFRequest( );
// lazy listen for ALL records with the listener shown above
req.addListenerForAllRecords( this );
HSSFEventFactory factory = new HSSFEventFactory( );
factory.processEvents( req,