Read excel and put cell data into HashMap

//Read excel row by row, put cell name and cell value to a map for each row.
HashMap getExpectedResult(int rowNum, String filePath, String sheetName){
    HashMap<String,String> map = new HashMap<String,String>();
    ArrayList<String> cellNames = getCellValues(0,filePath, sheetName);
    ArrayList<String> cellValues = getCellValues(rowNum,filePath, sheetName);

    for(int i=0; i<cellNames.size(); i++){
        String dataPointName = cellNames.get(i);
        String dataPointValue = cellValues.get(i);
        map.put(dataPointName, dataPointValue);
    }
    return map;
}    

ArrayList<String> getCellValues(int rowNum, String filePath, String sheetName){
    ArrayList<String> cellValues = new ArrayList<String>();
    try{
        File file = new File(filePath);
        XSSFWorkbook wb = new XSSFWorkbook(new FileInputStream(filePath));
        XSSFSheet sheet = wb.getSheet(sheetName);
        Row row = sheet.getRow(rowNum);
         String cellValue;

        if (row != null){
            for (int i=8; i<row.getPhysicalNumberOfCells(); i++){
                if(rowNum==0){
                    cellValue = row.getCell(i).getStringCellValue();
                }else{　　　　　　　　　　　　//if the cell value is blank
                    if(row.getCell(i).getCellType()==3){
                        cellValue = row.getCell(i).getStringCellValue();
                    }else{
                        cellValue = formatDecimal(row.getCell(i).getNumericCellValue());
                    }
                }
                cellValues.add(cellValue);
            }
        }
        return cellValues;
     }
     catch (Exception e){
        e.printStackTrace();
        return null;
     }
}

String formatDecimal(double value){
    DecimalFormat df = new DecimalFormat("#.#####");
    return df.format(value);
}