We can use POIFS if we had a document written in OLE 2 Compound Document Format, probably written using MFC, that you needed to read in Java.We can use HSSF if you needed to read or write an Excel file using Java (XLS).
Examples of POI3.0
Overview of the POI
APIs We can use POIFS if we had a document written in OLE 2
Compound Document Format, probably written using MFC, that you needed to
read in Java.We can use HSSF if you needed to read or write an
Excel file using Java (XLS). We can use HWPF for Word Documents , HSLF
for PowerPoint Documents and HPSF for Document Properties.You can also read
and modifyspreadsheets using POI API, although right now
writing is more mature.