Check out java.sql.PreparedStatement, combined with a BLOB field in your database. Open an InputStream to the uploaded file, and call setBinaryStream with it.
There might be a problem with this if you don't know the file size and either your database driver is not built for Java 6, or you're stuck to Java 5.0 or below for some reason - you need to pass the InputStream length (as an int) to the only setBinaryStream method available in Java 5.0 and below.
A solution could be using ByteArrayInputStream and ByteArrayOutputStream:
This could be memory consuming (you're storing the entire XLS file in memory) so it's really preferred if you can just retrieve the XLS file size without reading the contents.
I suspect he wanted to actually get the data in the Excel worksheet into rows in the database (I am assuming this from the query written). For that you should check up on using some third party framework e.g. Apache POI HSSF or ActiveXLS You can then read the data from the Excel sheets and then run them against the database using the query as necessary.