title: Only edit Excel sheet with Jexcel
body: <p>I have to create an application in java to help filling data in Excel file with multiple sheets. The problem is I need to call my function write every time I insert data and currently everytime it does replace my actual file by an new one.</p>
  
  <p>I searched on google some answers but I could'nt find anything. Currently for testing if an Excel Sheet exist I'm doing that :</p>
  
  <pre><code>    if(workbook.getSheet(Nom[0]) != null){
         workbook.createSheet(Nom[0], 0);
                  }
  </code></pre>
  
  <p>But the real problem come when I only want to write in an existing Excel file :</p>
  
  <pre><code>if(file.exists() &amp;&amp; !file.isDirectory()) 
              workbook = Workbook.getWorkbook(file);
          else
              workbook = Workbook.createWorkbook(file,wbSettings);
  </code></pre>
  
  <p>And the method getWorkbook return Workbook type instead of WritableWorkbook. </p>
  
  <p>What should I do to write in an existing Excel file ?</p>
  
  <p>Thank you </p>