How to process old excel .xls files using POI?

Question

I switched from jxl to poi since POI has more features. However, I wasn\'t able to process the xls files that were generated in the old format. Now I am getting this error:<

Answer 1

as per my knowledge you can use this code to read excel files of the .xls format

FileInputStream in=new FileInputStream(new File("filename.xls"));
Wookbook wb=new HSSFWorkbook(in);

to read the new excel versions(2007 and up):

 FileInputStream in=new FileInputStream(new File("filename.xls"));
    Wookbook wb=new XSSFWorkbook(in);

external jar files that you will need:

 1. poi-3.9 
 2. dom4j-1.6.1
 3. XMLbeams-2.5.0

if you're work only requires you to work with .xls then only poi-3.0 will suffice. You need the other jars to work witht the new versions of excel.

Answer 2

For old Excel format files, you have the following alternatives:

1. HSSF, the POI implementation of the Excel '97(-2007) file format.
   • If you just want to extract the textual content, then you can use OldExcelExtractor which will pull only the text and numbers from the file.
   • If you need the values from a specific cells, then you'll need to take an approach a bit like OldExcelExtractor, process the file at the record level, and check for the co-ordinates on OldStringRecord, NumberRecord, OldFormulaRecord and friends.
2. Like you already mentioned, JXL can handle some cases too.
3. Use a JDBC/ODBC driver. It is not as flexible as HSSF but for some old formats it is the only way to extract the information.