Busy Developers' Guide to HSSF Features

Reading and Rewriting Workbooks

POIFSFileSystem fs =
new POIFSFileSystem(new FileInputStream("workbook.xls"));
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row = sheet.getRow(2);
HSSFCell cell = row.getCell((short)3);
if (cell == null)
cell = row.createCell((short)3);
cell.setCellType(HSSFCell.CELL_TYPE_STRING);
cell.setCellValue("a test");

// Write the output to a file
FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();