I was reading the Apache poi guide: https://poi.apache.org/spreadsheet/quick-guide.html

And I decided to follow along and type the code into my Eclipse project, and while writing the "Reading and Rewriting Workbooks" section, I got this error in eclipse:

CellType cannot be resolved to a variable

And I was wondering why? I found on another post in Stack Overflow to change this line:

cell.setCellType(CellType.STRING);

to:

cell.setCellType(HSSFCellType.STRING);//or XSSFCell

But it doesn't work, is there anything wrong with my code? (Which btw, I copied and pasted from apache's website)

 InputStream inp = new FileInputStream("workbook.xls");

 Workbook wb = WorkbookFactory.create(inp);
 Sheet sheet = wb.getSheetAt(0);
 Row row = sheet.getRow(2);
 Cell cell = row.getCell(3);
 if (cell == null)
     cell = row.createCell(3);
 cell.setCellType(CellType.STRING);
 cell.setCellValue("a test");

 //Write 
 FileOutputStream fileOut = new FileOutputStream("workbook.xls");
 wb.write(fileOut);
 fileOut.close();