How to implement authentication mechanism in Java EE 6

I'm trying to learn Java EE 6 and i'm just wondering how to implement authentication mechanism in Java EE 6.

Here is the Java EE 6 authentiction example:

    public void login() {
    if (account.authenticate(name, password) == null) {
        message = "Invalid user name or password!";
    } else {
        message = " Login successful";
        FacesContext context = FacesContext.getCurrentInstance();
        HttpServletRequest request = (HttpServletRequest) context.getExternalContext().getRequest();
        try {
            request.login(this.name, this.password);
            Principal principal = FacesContext.getCurrentInstance().getExternalContext().getUserPrincipal();
            name = principal.getName();
        } catch (ServletException e) {
            // Handle unknown username/password in request.login().
            context.addMessage(null, new FacesMessage("Unknown login"));
        }
    }
}

I have a following questions:

1. How request.login function check name and password? It isn't know user entity?
2. If it isn't right way. How to implement standart authentication mechanism

In finally thank you for your advise and i need a very good tutorials or advise.