title: Adding data to a new cell in excel without deleting the previous cell
body: <p>When I try to add new data to this xls file, I lose my previous data. How can I add new information to new cells and save it?</p>
  
  <p>My code is Apache POI:</p>
  
  <pre><code>Workbook w = new HSSFWorkbook();
  
  Sheet s = w.createSheet("new");   
  
  Cell a = s.createRow(0).createCell(0);    
  Cell b = s.createRow(0).createCell(1);    
  a.setCellValue(jTextField1.getText());    
  
  try {
      FileOutputStream f = new FileOutputStream("C://NEW.xls");
      w.write(f);
      w.close();`
  } catch (Exception e) {
  
  }
  </code></pre>