In a servlet based artifact, such as @WebServlet, @WebFilter and @WebListener, you can grab a "plain vanilla" JSF @ManagedBean @RequestScoped by:

Bean bean = (Bean) request.getAttribute("beanName");

and @ManagedBean @SessionScoped by:

Bean bean = (Bean) request.getSession().getAttribute("beanName");

and @ManagedBean @ApplicationScoped by:

Bean bean = (Bean) getServletContext().getAttribute("beanName");

Note that this prerequires that the bean is already autocreated by JSF beforehand. Else these will return null. You d then need to manually create the bean and use setAttribute("beanName", bean).

If you re able to use CDI @Named instead of the since JSF 2.3 deprecated @ManagedBean, then it s even more easy, particularly because you don t anymore need to manually create the beans:

@Inject
private Bean bean;

Note that this won t work when you re using @Named @ViewScoped because the bean can only be identified by JSF view state and that s only available when the FacesServlet has been invoked. So in a filter which runs before that, accessing an @Injected @ViewScoped will always throw ContextNotActiveException.

Only when you re inside @ManagedBean, then you can use @ManagedProperty:

@ManagedProperty("#{bean}")
private Bean bean;

Note that this doesn t work inside a @Named or @WebServlet or any other artifact. It really works inside @ManagedBean only.

If you re not inside a @ManagedBean, but the FacesContext is readily available (i.e. FacesContext#getCurrentInstance() doesn t return null), you can also use Application#evaluateExpressionGet():

FacesContext context = FacesContext.getCurrentInstance();
Bean bean = context.getApplication().evaluateExpressionGet(context, "#{beanName}", Bean.class);

which can be convenienced as follows:

@SuppressWarnings("unchecked")
public static <T> T findBean(String beanName) {
    FacesContext context = FacesContext.getCurrentInstance();
    return (T) context.getApplication().evaluateExpressionGet(context, "#{" + beanName + "}", Object.class);
}

and can be used as follows:

Bean bean = findBean("bean");

See also:

• Backing beans (@ManagedBean) or CDI Beans (@Named)?

I use the following method:

public static <T> T getBean(final String beanName, final Class<T> clazz) {
    ELContext elContext = FacesContext.getCurrentInstance().getELContext();
    return (T) FacesContext.getCurrentInstance().getApplication().getELResolver().getValue(elContext, null, beanName);
}

This allows me to get the returned object in a typed manner.

Have you tried an approach like on this link? I m not sure if createValueBinding() is still available but code like this should be accessible from a plain old Servlet. This does require to bean to already exist.

http://www.coderanch.com/t/211706/JSF/java/access-managed-bean-JSF-from

 FacesContext context = FacesContext.getCurrentInstance();  
 Application app = context.getApplication();
 // May be deprecated
 ValueBinding binding = app.createValueBinding("#{" + expr + "}"); 
 Object value = binding.getValue(context);

You can get the managed bean by passing the name:

public static Object getBean(String beanName){
    Object bean = null;
    FacesContext fc = FacesContext.getCurrentInstance();
    if(fc!=null){
         ELContext elContext = fc.getELContext();
         bean = elContext.getELResolver().getValue(elContext, null, beanName);
    }

    return bean;
}

I had same requirement.

I have used the below way to get it.

I had session scoped bean.

@ManagedBean(name="mb")
@SessionScopedpublic 
class ManagedBean {
     --------
}

I have used the below code in my servlet doPost() method.

ManagedBean mb = (ManagedBean) request.getSession().getAttribute("mb");

it solved my problem.

I use this:

public static <T> T getBean(Class<T> clazz) {
    try {
        String beanName = getBeanName(clazz);
        FacesContext facesContext = FacesContext.getCurrentInstance();
        return facesContext.getApplication().evaluateExpressionGet(facesContext, "#{" + beanName + "}", clazz);
    //return facesContext.getApplication().getELResolver().getValue(facesContext.getELContext(), null, nomeBean);
    } catch (Exception ex) {
        return null;
    }
}

public static <T> String getBeanName(Class<T> clazz) {
    ManagedBean managedBean = clazz.getAnnotation(ManagedBean.class);
    String beanName = managedBean.name();

    if (StringHelper.isNullOrEmpty(beanName)) {
        beanName = clazz.getSimpleName();
        beanName = Character.toLowerCase(beanName.charAt(0)) + beanName.substring(1);
    }

    return beanName;
}

And then call:

MyManageBean bean = getBean(MyManageBean.class);

This way you can refactor your code and track usages without problems.