สร้างตัวแปร Session Scroped ใน Request Scroped ManageBean (BackingBean)

import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.context.FacesContext;

@ManageBean
@RequestScoped
public class Users {

     public Users(){
        if(getUser() == null){
            setUser(new User());
        }
    }

    public User getUser(){
        return getSessionMap().get("user");
    }

    public void setUser(User user){
        getSessionMap().put("user", user);
    }

    private Map<String, Object> getSessionMap(){
        return FacesContext.getCurrentInstance()
                    .getExternalContext()
                    .getSessionMap();
    }
}