Excel is Microsoft. Java is not. Nevertheless there are ways to manipulate the XLS-format from Java.
Some Open Source solutions are listed here:
„Handle Excel files“ by Réal Gagnon
I tested two of them:
- JXL
- POI
Jxl is straightforward and easy to use. POI is for all kind of Mircosoft formats, not only for Excel. IMHO it is a little more tricky to use.