title: How to set cell type as string in Apache POI XSSF 4.10?
body: <p>I'm trying to set the cell value as String using Apache POI XSSF 4.10 .</p>
  
  <p>I have used the code</p>
  
  <p>sheet.getRow(i).getCell(k).setCellType(CellType.STRING); but it throws null pointer exception.</p>
  
  <p>Please help</p>