What is missing ?? - JDBC and webdynpro

Question

Hello!!:
I'm traying to get some data vias JDBC from a Data base to display info in a webdynpro project's view.
The code is:
public void wdDoInit()
    //@@begin wdDoInit()
  wdContext.nodeAddressbook().invalidate();
  IPrivateAddressbookView.IAddressbookNode
  addressNode = wdContext.nodeAddressbook();
  IPrivateAddressbookView.IAddressbookElement addressElement;
  try {
       InitialContext ctx = new InitialContext();
     Object obj = (Object)ctx.lookup("jdbc/PDIM");
     DataSource ds = (DataSource)PortableRemoteObject.narrow(obj, DataSource.class);
     Connection con = ds.getConnection();
     Statement stmt = con.createStatement();
     ResultSet rs = stmt.executeQuery("SELECT * FROM INTERNOS" );
     String nombre;
     String departamento;
      con.close();
  }catch (SQLException e) {
          // handle exception
     System.out.println(e.getCause());
      System.out.println(e.getMessage());
  }catch (NamingException e) {
          // handle exception
     System.out.println(e.getCause());
      System.out.println(e.getMessage());
  }catch (Exception e){
          // handle exception
            System.out.println(e.getCause());
            System.out.println(e.getMessage());
at line:
Object obj = (Object)ctx.lookup("jdbc/PDIM"); an Naming exception is throw, it says:
com.sap.engine.services.jndi.persistent.exceptions.NameNotFoundException: Object not found in lookup of PDIM.
PDIM = alias and name of de data base.
The connector and alias are well difine in the portal as I look up for some steps to do it at the SDN an all of them were well done. I was wondering if there's some file, as data-source-aliases.xml or something like that's missing (what and where should I put it?).
All the examples using JDBC that I saw were with EJB + Web dynpro, not just Webdynpro and JDBC. THERE IS NOT EJB ON MY PROJECT.
Thanks a lot for your time.

Answer 1

Nagarajan Kumarappan Thanks a lot for your answer.
You said:
"Note:This should be added only if the alias does not exist."
by that you mean "if the alias SAP/PDIM is NOT display on the aliases'list"
is it ok? or the alias could have been created from the portal side, this is
htp://<host>:50000/irj/portal  --> system configurations --> portal content -->(from context menu) New --> System
THANKS!!