I could see two interpretations:

1. you get multiple rows back.

2. you ran reuse the PreparedStatement for another query.

I don't see how you could get multiple ResultSets literally back from
the same query since the method signature does not allow for it.

Hi. A single prepared statement or even a plain statement can easily
return multiple result sets for a single execution, if the DBMS will
cooperate. Sybase and MS for example:

create procedure myproc as
begin
    select * from mytable1
    update mytable2 set foo = 'bar'
    select * from mytable3 where foo = 'bar'
end

This procedure will return two result sets with an update count
in the middle. The jdbc to process this procedure and
get all the output is:

ResultSet r = s.executeQuery("myproc");
while (r.next())... // fully process first result set
r.close();
s.getMoreResults();
int myUpdateCount = s.getUpdateCount();
s.getMoreResults();
r = s.getResultSet(); // get second result set
while (r.next()) ...
r.close();

The canonical form for a callable statement handling an arbitrarily
complex procedure is shown below.

    CallableStatement cstmt1 = conn.prepareCall("{ ? = call sp_myname(?)}");

    cstmt1.registerOutParameter(1, java.sql.Types.INTEGER);
    cstmt1.registerOutParameter(2, java.sql.Types.VARCHAR);

    boolean firstReturnIsAResultSet = cstmt1.execute();

    while (true)
      {
        ResultSet rs    = cstmt1.getResultSet();
        int updateCount = cstmt1.getUpdateCount();

        // If there are no more results or counts, we're done.
        if (rs == null && updateCount == -1)
          break;

        // Check to see if there is a ResultSet
        if (rs != null) {
          while (rs.next()) {
            System.out.println("Get first col by id:" + rs.getString(1));
          }
          rs.close();
        } // Otherwise, there will be an update count
        else {
          System.out.println("Update count = " + updateCount);
        }
        cstmt1.getMoreResults();
      }

    // Best to retrieve status after all result sets and update counts
    // have been retrieved.
    System.out.println( "Output status: " + cstmt1.getInt(1));
    System.out.println( "Output param:  " + cstmt1.getString(2));

    cstmt1.close();

Joe Weinstein at BEA

Oh, and for Oracle procedures, which can't return results inline like fresh SQL,
they provide for cursors as output parameters for procedures, so you can get
multiple result sets from a given procedure execution by doing a getObject()
for the output parameters and casting them to result sets.
Joe Weinstein at BEA

As Joe described, a stored procedure call can return multiple results.

In addition, you might send multiple SQL commands to a single prepared statement, thus
you will receive multiple results (if supported by the backend DBMS). For example:

 prepStnt = conn.prepareStatement("SELECT*FROM tab1;SELECT*FROM tab2");

... this will produce 2 resultsets (for brevity, I didn't use ? parameters, though they
are allowed.)

Note: the multiple commands can be a mixture of queries, updates and control commands.