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From Felipe Schnack <feli...@ritterdosreis.br>
Subject Re: Filters, MVC, ResultSets
Date Tue, 29 Oct 2002 11:15:04 GMT
  Of course there is copying, or you'll never could be disconnected :-)
  And actually, jxutil uses an ArrayList... better than a Vector, as it
isn't synchronized, but If you don't need unordered readings, an
LinkedList would be much faster, IMHO

On Tue, 2002-10-29 at 10:09, V. Cekvenich wrote:
> Or a disconected rowset, so no copying.
> 
> Ex:http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/basicportal_07/src/basicWebLib/org/commons/DAO/BasicDAOImpl.java?rev=1.2&content-type=text/vnd.viewcvs-markup
> 
> .v
> 
> 
> Felipe Schnack wrote:
> >   I think a LinkedList would be better performance-wise, wouldn't it?
> > 
> > On Mon, 2002-10-28 at 21:01, German Augusto Niebles Alvarez wrote:
> > 
> >>I suggest you use vectors and beans (collection of beans) to poblate rs
> >>and then close de resultset, and use a class to connect to database
> >>(jdbchelper class), i send you an example:
> >>================================================
> >>
> >>
> >>  // Obtiene la informacion acerca de la empresa
> >>  public Vector obtenerInformacionOrganizacion()
> >>              // throws SQLException,javax.naming.NamingException
> >>  {
> >>
> >>    Vector contenedorRazonSocial = new Vector();
> >>
> >>    Connection connection = null;
> >>    String selectRazonSocialStr =
> >>      "SELECT * FROM tblRazonSocial";
> >>
> >>    PreparedStatement selectStatement = null;
> >>
> >>    try {
> >>
> >>      // Obtiene una conexion a la base de datos, requiere Try
> >>      connection = jdbcAccess.getConnection();
> >>
> >>      // Prepara la sentencia de Busqueda
> >>      selectStatement =
> >>connection.prepareStatement(selectRazonSocialStr);
> >>
> >>      // Obtiene el resultset
> >>      ResultSet rs = selectStatement.executeQuery();
> >>
> >>      // Si el rs tiene next es que tiene un registro con la informacion
> >>acerca de la empresa
> >>
> >>      FachadaRazonSocialBean facRazonSocialBean;
> >>
> >>      if (rs.next()) {
> >>
> >>        facRazonSocialBean = new FachadaRazonSocialBean();
> >>
> >>        facRazonSocialBean.setNit(rs.getString("nit"));
> >>        facRazonSocialBean.setNombre(rs.getString("nombre"));
> >>        facRazonSocialBean.setDireccion(rs.getString("direccion"));
> >>        facRazonSocialBean.setTelefono(rs.getString("telefono"));
> >>        facRazonSocialBean.setEMail(rs.getString("email"));
> >>       
> >>facRazonSocialBean.setDireccionWeb(rs.getString("direccionWeb"));
> >>        facRazonSocialBean.setCodigoIAC(rs.getString("codigoIAC"));
> >>
> >>        contenedorRazonSocial.add(facRazonSocialBean);
> >>
> >>      }
> >>      contenedorRazonSocial.trimToSize();
> >>
> >>      // Cierra el Resultset
> >>      rs.close();
> >>      jdbcAccess.cleanup(connection, selectStatement,null);
> >>
> >>    }
> >>
> >>    // Area de obtencion de Excepciones
> >>    catch(NamingException ne) {
> >>      System.out.println("NamingException in JDBCAccess :" + ne);
> >>    }
> >>
> >>    catch (SQLException sqle) {
> >>   System.out.println("SQLException in JDBCAccess:" + sqle);
> >> }
> >>
> >> catch (Exception e)
> >> {
> >>   System.out.println("Exception In JDBCAccess:" + e);
> >> }
> >>    finally {
> >>    return contenedorRazonSocial;
> >>
> >>    }
> >>  }
> >>
> >>
> >>
> >>======================================================
> >>
> >>Atentamente,
> >>
> >>
> >>Germán Niebles
> >>Analista de Información
> >>Tel 4-93-86-00 Ext 7053
> >>
> >>
> >>>>>hookomjj@uwec.edu 10/28 4:39 p.m. >>>
> >>>>
> >>Hey All,
> >>
> >>Everyone says for performance purposes, working directly with the
> >>resultset is optimal.  But, with MVC, we can't just push the RS to the
> >>JSP to display and ignore closing.
> >>
> >>Is it possible with Filters to do a M->C1->V->C2 where C1 sets
> >>resultsets in the request, then pushes the response up to the JSP to
> >>render the content and then closes the resultset after rendering.  I
> >>know 'programatically' it would work, but, I'm wondering about
> >>exceptions and making sure that the resultsets get closed.  An example
> >>would be passing the request/response to the JSP, but then an exception
> >>occurs up the chain, does the exception trickle back down through the
> >>filters no matter what to catch and close my JDBC items?
> >>
> >>Best Regards,
> >>Jacob Hookom
> > 
> 
> 
> 
> 
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> 
-- 

Felipe Schnack
Analista de Sistemas
felipes@ritterdosreis.br
Cel.: (51)91287530
Linux Counter #281893

Faculdade Ritter dos Reis
www.ritterdosreis.br
felipes@ritterdosreis.br
Fone/Fax.: (51)32303328


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