엑셀파일 읽어와서 수정하기

InputStream inp = new FileInputStream("workbook.xls"); //InputStream inp = new FileInputStream("workbook.xlsx"); Workbook wb = WorkbookFactory.create(inp); Sheet sheet = wb.getSheetAt(0); Row row = sheet.getRow(2); Cell cell = row.getCell(3); if (cell == null) cell = row.createCell(3); cell.setCellType(Cell.CELL_TYPE_STRING); cell.setCellValue("a test"); // Write the output to a file FileOutputStream fileOut = new FileOutputStream("workbook.xls"); wb.write(fileOut); fileOut.close();