How to register a JSF managed bean programmatically?

Question

I\'d like to register/add a Managed Bean class programmatically (from within a Servlet init()) into application scope. How can I do that with JSF 1.2?

Answer 1

The following code registers the managed bean correcly using FacesContext, but it requires the servlet request and response. You could use the code and initialize it lazily using servlet and not during the init.

Usage:

UserBean ub = (UserBean) 
    Example.getBean(servletRequest, servletResponse, "user", UserBean.class);

Source:

import javax.el.ExpressionFactory;
import javax.el.ValueExpression;
import javax.faces.FactoryFinder;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.context.FacesContextFactory;
import javax.faces.lifecycle.LifecycleFactory;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

class Example {

    public static Object getBean(HttpServletRequest request, HttpServletResponse response, String beanName, Class expectedType){
        FacesContext ctx = getFacesContext(request, response);
        ValueExpression vex = ctx.getApplication().getExpressionFactory().createValueExpression(ctx.getELContext(), "#{"+beanName+"}", expectedType);
        return vex.getValue(ctx.getELContext());
    }

    private static FacesContext getFacesContext(HttpServletRequest request, HttpServletResponse response) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        if (facesContext == null) {
            facesContext = ((FacesContextFactory) FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY)).
                getFacesContext(request.getSession().getServletContext(), request, response, 
                ((LifecycleFactory) FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY))
                .getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE));

            InnerFacesContext.setFacesContextAsCurrentInstance(facesContext);
            facesContext.setViewRoot(facesContext.getApplication().getViewHandler().createView(facesContext, ""));
        }
        return facesContext;
    }

    private abstract static class InnerFacesContext extends FacesContext {
        protected static void setFacesContextAsCurrentInstance(FacesContext facesContext) {
            FacesContext.setCurrentInstance(facesContext);
        }
    }
}