构造函数File（String）是未定义的…我如何删除这个错误？

我怎样才能修复File(String) is undefined错误？

 int classi(String s) throws BiffException, IOException { String[] words = s.split(" "); Workbook workbook = Workbook.getWorkbook(new File("D:\feat.xls")); Sheet sheet = workbook.getSheet(0); }