title: how to make cell as read-only in excel using apachi-POI
body: <p>i have a drop down list contains some options, and for example two cells. what i need is regarding the selected option turn one of the cells to editable and the other to read-only and vise-versa.</p>
  
  <pre><code>FileOutputStream fos;
  try {
      fos = new FileOutputStream("D:\\POIXls.xls");
      Workbook workbook = new XSSFWorkbook();
      Sheet sheet = workbook.createSheet("new Sheet");
      DataValidationHelper dvHelper = sheet.getDataValidationHelper();
      DataValidationConstraint dvConstraint = 
                    dvHelper.createExplicitListConstraint(new String[] { "cell 1 edit","cell 2 edit"});
     CellRangeAddressList addressList = new CellRangeAddressList(0, 2, 0, 0);
     DataValidation validation = dvHelper.createValidation(dvConstraint, addressList);
  
     if (validation instanceof XSSFDataValidation) {
         validation.setSuppressDropDownArrow(true);
         validation.setShowErrorBox(true);
     } else {
         validation.setSuppressDropDownArrow(false);
     }
  
     sheet.addValidationData(validation);
     workbook.write(fos);
     fos.flush();
     fos.close();
  }catch(Exception e){//catch code}
  </code></pre>
  
  <p>i need to know how to make that xls file make these cells editable/read-only according to the user's selection.
  VB code may be helpful also.</p>