Re: Can the FacesContext be Accessed from Outside of a Backing Bean?

[Julian Ray]

Hi Mike,

Here is some code which shows how we get the faces context in a servlet. It also has a utility method retrieving managed beans.

public abstract class AbstractFacesServlet extends HttpServlet {
       
    /** Creates a new instance of AbstractFacesServlet */
    public AbstractFacesServlet() {
        super();
    }
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
    }    
    protected abstract void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
    
    /** Handles the HTTP <code>GET</code> method.
    * @param request servlet request
    * @param response servlet response
    */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        processRequest(request, response); 
    }
    protected void log(FacesContext facesContext, String message) {
        facesContext.getExternalContext().log(message);
    }
    /** Handles the HTTP <code>POST</code> method.
    * @param request servlet request
    * @param response servlet response
    */ 
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        processRequest(request, response);
    }
    protected FacesContext getFacesContext(HttpServletRequest request, HttpServletResponse response) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        if (facesContext == null) {
 
            FacesContextFactory contextFactory  = (FacesContextFactory)FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
            LifecycleFactory lifecycleFactory = (LifecycleFactory)FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY); 
            Lifecycle lifecycle = lifecycleFactory.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);
 
            facesContext = contextFactory.getFacesContext(request.getSession().getServletContext(), request, response, lifecycle);
 
            // Set using our inner class
            InnerFacesContext.setFacesContextAsCurrentInstance(facesContext);
 
            // set a new viewRoot, otherwise context.getViewRoot returns null
            UIViewRoot view = facesContext.getApplication().getViewHandler().createView(facesContext, "cms");
            facesContext.setViewRoot(view);                
        }
        return facesContext;
    }
    protected Object getBean(String beanName, FacesContext facesContext) {        
        return getApplication(facesContext).getVariableResolver().resolveVariable(facesContext, beanName);
    }
    // You need an inner class to be able to call FacesContext.setCurrentInstance
    // since it's a protected method
    private abstract static class InnerFacesContext extends FacesContext {
        protected static void setFacesContextAsCurrentInstance(FacesContext facesContext) {
            FacesContext.setCurrentInstance(facesContext);
        }
    }     
}


----- Original Message ----
From: Mike Duffy <[EMAIL PROTECTED]>
To: users@myfaces.apache.org
Sent: Wednesday, May 17, 2006 12:43:28 PM
Subject: Can the FacesContext be Accessed from Outside of a Backing Bean?

If I call the following from inside a backing bean, everything works fine:

User user = (User)
FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get(Constants.USER_KEY);

However, if I make the same call from an object in the session or from a utilty class, I get a
null pointer on "FacesContext.getCurrentInstance()".

Can the FacesContext be accessed from outside of a backing bean?

Thx.

Mike

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