private Workbook openExcelFile() throws IOException, BiffException, Exception {
		Workbook workbook;
		workbook = Workbook.getWorkbook(new java.io.File(fileName));
		Sheet sheet = workbook.getSheet(0);
		sw=new ExcelSheetWrapper(sheet);


		//若未设置tableName，则从tableLine中去读
		if(tableName==null || tableName.length()==0){

			if(tableLine==0){
				throw new Exception("You must special import table name!");
			}
			tableName=sw.getString(0, tableLine-1, null);
			if(tableName==null || tableName.length()==0){
				throw new Exception("Table name not found in excel file(CELL:A"+(tableLine)+")!");
			}
		}
		return workbook;
	}