Dès que fileouttream est exécuté, il change le format de fichier. Ci-dessous mon code:FileOutputStream webdata = nouveau FileOutputStream();
FileInputStream input=new FileInputStream(path);
System.out.println("input");
XSSFWorkbook wb=new XSSFWorkbook(input);
System.out.println("wb");
XSSFSheet sh=wb.getSheet("Sheet1");
System.out.println("sh");
XSSFRow row=sh.getRow(2);
System.out.println("row");
FileOutputStream webdata=new FileOutputStream(path);
System.out.println("wedata");
row.createCell(2).setCellValue("hi");
System.out.println("print");
wb.write(webdata);
System.out.println("end");
org.apache.poi.openxml4j.exceptions.NotOfficeXmlFileException
D'où provient l'exception? – EJP