JDBC question: Which class is returned?

I am doing some queries using JDBC. I use the ResultSet.getObject()
method to get the result object. This works fine with SQL VARCHAR,
etc, but there is a big problem when I try it with an INT4.

For example:

Object obj = result.getObject(i);

It gets the object just fine but then I can't do anything with the
object. I can't do this:

System.out.println("The result is: " + (String) obj);

or anything else. I am guessing that the problem may be that it is
trying to return an integer type, which is not an object. Any
sugestions on this?

One thing I think I could do is to try to detect the type using
MetaData.getResultType() or something, and then call
ResultSet.getInt() or whatever is appropriate. Is this the best way
to do it?

Thanks