急问难题关于postgre数据库

public void init(ServletConfig config) throws ServletException
    {
        String loginUser = "postgres";
        String loginPasswd = "supersecret";
        String loginUrl = "jdbc:postgresql://localhost:port/yourdatabasename";        // Load the PostgreSQL driver
        try 
           {
              Class.forName("org.postgresql.Driver");
              dbcon = DriverManager.getConnection(loginUrl, loginUser, loginPasswd);
            }
        catch (ClassNotFoundException ex)
            {
               System.err.println("ClassNotFoundException: " + ex.getMessage());
               throw new ServletException("Class not found Error");
            }
        catch (SQLException ex)
            {
               System.err.println("SQLException: " + ex.getMessage());
            }
    }