I have a utility for export and import of data. I am saving a file in excel format and then importing the same file to the database. When I try to import the same exported file, I get IOException - Invalid Header signature. But, if I first open the exported file in MS excel and then do - save as (in excel format) and then Import that saved file, I don't get the error. I find out that when I export the file, it saves the file in text format only along with with .xls extention. The MS Excel converts the text file into Excel while reading. But the file exported is not actually an excel worksheet so the Import of the same file does not works. Is there any solution to this problem. I am already using response.setContentType("application/vnd.ms-excel");
What kind of export and import code is that - do you have control over it (meaning, can you fix it)? If not, I'd talk to the vendor of whatever software you're using, and get a version that doesn't export a non-XLS file as XLS.