title: Apache POI XSSFCell not taking Cell.CellType as argument
body: <p>Ahoi there,</p>
  
  <p>I am trying to set the CellType of an XSSFCell. Basically I want to have just on set of methods to export a HSSF and a XSSFWorkbook and according to the API it SHOULD work.</p>
  
  <pre><code>   Workbook workbook = new XSSFWorkbook(); //Alternatively HSSFWorkbook
     Sheet sheet = workbook.createSheet();
          Row headerRow = sheet.createRow(0);
          for (int x = 0; x &lt; exportColumns.size(); x++) {
              Cell createCell = headerRow.createCell(x);
              //Exception
              createCell.setCellType(CellType.STRING);
              //
              createCell.setCellValue(exportColumns.get(x));
          }
  </code></pre>
  
  <p>But I get the following NetBeans runtime hint when using an XSSFWorkbook (HSSF works fine):</p>
  
  <p>createCell.setCellType(CellType.STRING) = >None of the "setCellType" methods in class "org.apache.poi.xssf.usermodel.XSSFCell" takes parameters of types "(org.apache.poi.ss.usermodel.CellType)".&lt;</p>
  
  <p>Problem is, that in the official API Doc the exactly some method shows up and I am using the latest Version. (April '17)
  <a href="https://poi.apache.org/apidocs/org/apache/poi/xssf/usermodel/XSSFCell.html#setCellType(org.apache.poi.ss.usermodel.CellType)" rel="nofollow noreferrer">https://poi.apache.org/apidocs/org/apache/poi/xssf/usermodel/XSSFCell.html#setCellType(org.apache.poi.ss.usermodel.CellType)</a></p>
  
  <p>Anyone has some ideas to this? I dont want to have totally redundant code, just because I have to duplicate everything because of the CellTypes...</p>
  
  <p>Update:</p>
  
  <p>Version 3.1.6 from <a href="https://mvnrepository.com/artifact/org.apache.poi/poi" rel="nofollow noreferrer">https://mvnrepository.com/artifact/org.apache.poi/poi</a>. </p>
  
  <p>Basically that is a runtime NetBeans Hint. The actual Exception is:</p>
  
  <pre><code> Caused by: java.lang.AbstractMethodError: org.apache.poi.xssf.usermodel.XSSFCell.setCellType(Lorg/apache/poi/ss/usermodel/CellType;)V
      at de.htwk.leipzig.maxsolutions.service.ExportService.exportToExcel(ExportService.java:134)
      at de.htwk.leipzig.maxsolutions.service.ExportService.exportFile(ExportService.java:91)
      at de.htwk.leipzig.maxsolutions.controller.ExcelExportViewController.startExport(ExcelExportViewController.java:185)
      at de.htwk.leipzig.maxsolutions.controller.ExcelExportViewController.handleSaveAction(ExcelExportViewController.java:105)
      ... 58 more
  </code></pre>