Re: Multiple open ResultSets not allowed?

Jeff Kolesky wrote:
> Just to make sure I wasn't looking at the code incorrectly, I wrote the
> following test code, making sure not to close the connection before
> trying to get data from the result set:
>
>     Connection con = DB.getConnection();
>     Statement s1 = con.createStatement();
>     ResultSet rs1 = s1.executeQuery("SELECT * FROM table1");
>     while(rs1.next())
>     {
>         String col = rs1.getString("col");
>         System.out.println(col);
>         Statement s2 = con.createStatement();
>         ResultSet rs2 = s2.executeQuery("SELECT * FROM table2");
>         while(rs2.next())
>         {
>             String col2 = rs2.getString("col");
>             System.out.println("\t" + col2);
>         }
>         rs2.close();
>         s2.close();
>     }
>     rs1.close();
>     s1.close();
>     con.close();
>
> Running this code throws the same exception.  Looks like the connection
> is being closed incorrectly by the driver, or more likely that ResultSet
> data (Vector rows) is being set to null somehow.

All,
Something definitely seems to be resetting rows to null when a second
ResultSet is created on a Connection where another already exists. We
see this problem when we request a second rs (differing only by an ORDER
BY from the original) in a UI app we have. Inserting an initialization:

        //don't know how this happens, but...
        if (rows == null)
        {
          rows = new Vector();
        }

in the code for AbstractJdbc2ResultSet#absolute(int index) cured a null
pointer exception, but of course this is completely unsatisfactory.
Haven't had a chance to track down where this var gets set yet...

                              Rich Cullingford
                              rculling@sysd.com