title: org.apache.poi writing xls formula of cells sum
body: <p>I have to write xls formula that will sum few cells from one column.
  The output in xls of that formula look that:</p>
  
  <pre><code>SUM(F5;F9;F13;F16)
  </code></pre>
  
  <p>I've created that formula in org.apache.poi library.</p>
  
  <pre><code>Cell cell = rowSum.createCell(j);
  cell.setCellType(Cell.CELL_TYPE_NUMERIC);
  
  // column number like (A or B) in excel to use in formula
  String x = CellReference.convertNumToColString(j);
  cell.setCellType(HSSFCell.CELL_TYPE_FORMULA);
  
  // for total sum row
  String totalSumFormula = "SUM(";
  
  for(int s=0; s&lt;sumRowNumbers.size(); s++) {
  int tempSumRowNumber = sumRowNumbers.get(s);
  tempSumRowNumber++;
      totalSumFormula += (x + tempSumRowNumber);
  
      if(s+1 != sumRowNumbers.size()) {
          totalSumFormula += ";";
  } else {
      totalSumFormula += ")";
      }
   }
   cell.setCellFormula(totalSumFormula);
  </code></pre>
  
  <p>but unfortunatelly I am getting an error that I cant understand:</p>
  
  <pre><code>[FormulaParseException: Parse error near char 6 ';' in specified formula 'SUM(F5;F9;F13;F16)'. Expected ',' or ')'] 
  </code></pre>
  
  <p>Can You give me any advise? How to deal with it?</p>