Unable to read excel files in java getting 2 below

Question

I am trying to read xls and xlsx files with below code and get data from it but i am able to read 70% of xl files i am having but for some i am getting below errors for remaining files some are giving 1st error and some are giving 2nd error

1)java.lang.IllegalArgumentException: The supplied POIFSFileSystem does not contain a BIFF8 'Workbook' entry. Is it really an excel file?

2)java.lang.IllegalArgumentException: Your InputStream was neither an OLE2 stream, nor an OOXML stream

Both above errors are coming for xlsx extension files

Why am i able to read some and not some files and is there any global solution to this

My java code:

FileInputStream input = new FileInputStream("/Users/Xl_Files/"+fileName);


        Workbook wb = WorkbookFactory.create(input);
        Sheet sheet = wb.getSheetAt(0);
String var = String.valueOf(sheet.getRow(Row).getCell(Colon));