excel文件含有数据有效性,下拉列表的形式。Workbook book;
WorkbookSettings settings = new WorkbookSettings();
book = Workbook.getWorkbook(myFile, settings);
if (book.getNumberOfSheets() == 0)
{
    System.out.println("No sheet!");
}
Sheet sheet = book.getSheet(0); //这一行报错Warning:  Cannot read drop down range Unrecognized token 43
java.lang.NullPointerException
at jxl.biff.DataValiditySettingsRecord.getFirstColumn(DataValiditySettingsRecord.java:237)
at jxl.read.biff.SheetReader.read(SheetReader.java:1009)
at jxl.read.biff.SheetImpl.readSheet(SheetImpl.java:686)
at jxl.read.biff.WorkbookParser.getSheet(WorkbookParser.java:252)
        ......
请问jxl如何读取含有数据有效性设置的excel文件???PS:如果清除excel的数据有效性,是不会报错的。