title: How to validate all the column of a particular header name in excel using POI api
body: <p>I have a excel with headers, empName, empId, Department. I need to provide dropdown for user to enter department Name. User should be able to entry only the values present in drop down. I tried below code but it is not validating department column.
  CellRangeAddressList addressList = new CellRangeAddressList(2, 2, 2, 2);
          DVConstraint dvConstraint = DVConstraint.createExplicitListConstraint(new String[] { "ACCOUNTS", "ISE", "SALES" });
          DataValidation dataValidation = new HSSFDataValidation(addressList, dvConstraint);
          dataValidation.setSuppressDropDownArrow(true);
          sheet.addValidationData(dataValidation);
          font.setFontHeightInPoints((short) 16);</p>