FileInputStream
fis=new FileInputStream("E:\\data.xlsx"); Workbook wb=WorkbookFactory.create(fis);
Sheet s=wb.getSheet("test");//sheet name
s.createRow(1).createCell(1).setCellValue("Java");
FileOutputStream fos = new FileOutputStream("E:\\data.xlsx");
wb.write(fos);
fos.close();
System.out.println("Success");
}