Kiran:
take a look at
iText for java-PDF conversions.
For Excel, if you are on Windows, probably the best way is to create an ODBC driver to the Excel file (yes, you can do that...) and read the document through the JDBC-ODBC bridge. if you cannot do that, then look at the
Jarkata POI API.
Piscis Babelis est parvus, flavus, et hiridicus, et est probabiliter insolitissima raritas in toto mundo.