String jndi="jdbc/база";
            InitialContext context= null ;
             try  {
                context =  new  InitialContext();
            }  catch  (NamingException ex) {
                ex.printStackTrace();
            }
            DataSource ds= null ;
             try  {
                ds = (DataSource) context.lookup(jndi);
            }  catch  (NamingException ex) {
            }
            Connection con= null ;
             try  {
                con = ds.getConnection();
            }  catch  (SQLException ex) {
                ex.printStackTrace();
            }