Knowledge brings fear ... Prosthetic Conscious

JSF allows one to add error, info, etc. messages during various phases of request processing by calling FacesContext.getCurrentInstance().addMessage(). It then allows these messages to be displayed in your presentation with the h:messages tag. Nice facility, as it allows messages to be associated with particular widgets on the page so one can say report a problem next to the widget where it occured. So far, so good.

The problem: if you are using request scoped beans, your messages don't display. They are lost. There is some discussion on the web about this being the correct behavior considering the JSF life cycle and request scoping. I don't buy that, because it works fine for session scoping and I find it hard to believe that the spec would allow the message facility to be broken for request scoped beans. I actually wonder if this is a bug on the JSF RI.  Maybe someone can explain the details. Suspiciously, all of the related JSF examples and tutorials out there use session scoped beans.

A clean way to get around this is to simply define a session scoped bean whose only purpose to add messages.

    <managed-bean>
        <managed-bean-name>messageHandler</managed-bean-name>
        <managed-bean-class>com.sun...MessageHandler</managed-bean-class>
        <managed-bean-scope>session</managed-bean-scope>
    </managed-bean>

Define a bean called MessageHandler, and add a single method addMessage() that simply delegates to FacesContext.getCurrentInstance().addMessage().

public class MessageHandler {
    public void addMessage(String id, FacesMessage fm) {
        FacesContext.getCurrentInstance().addMessage(id, new FacesMessage(msg));
    }
}

Now add this bean as a managed property of your request scoped beans:

    <managed-bean>
        <managed-bean-name>aBean</managed-bean-name>
        <managed-bean-class>com.sun...ABean</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>       
        <managed-property>
            <property-name>messageHandler</property-name>
            <value>#{messageHandler}</value>
        </managed-property>     
    </managed-bean>       

In your ABean implementation, add messages by calling getMessageHandler().addMessage(). This is clearly just a hack, but if you use request scoped beans and throwing JSF out the door isn't an option, you'll need it. I suppose the catch is if you're using request scoped beans, you may have a requirement to not be using them, in which cases this solution is invalid.