问题
I have a stateless EJB that acceses my database. I need this bean in a JSF 2 converter to retreive an entity object from the String value parameter. I'm using JEE6 with Glassfish V3.
@EJB annotation does not work and gets a NPE, because it's in the faces context and it has not access to the EJB context.
My question is:
Is it still possible to Inject this bean with a @Resource or other annotation, or a JNDI lookup, or do I need a workaround?
Solution
Do a JNDI lookup like this:
try {
ic = new InitialContext();
myejb= (MyEJB) ic
.lookup("java:global/xxxx/MyEJB");
} catch (NamingException e) {
e.printStackTrace();
}
回答1:
I never used JSF 2.0 (only 1.0), but chapter 5.4 of the spec says:
[...] allow the container to inject references to container managed resources into a managed bean instance before it is made accessible to the JSF application. Only beans declared to be in request, session, or application scope are eligble for resource injection.
But so far I understand, a JNDI lookup should do the trick.
回答2:
Other (yet not so pretty) solution may be using binding instead of converterId. Using JSF managed beans only:
<f:converter binding="#{app.personConverter}" />
Where appBean stands for something like:
@ManagedBean(name="app")
@ApplicationScoped
class AppBean {
@EJB
private PersonService ps;
private Converter personConverter;
}
There MAY be a nicer solution in CDI-style (JSR-299) but i've failed to make this one running:
<f:converter binding="#{cdiBean}" />
Where cidBean ought to be:
@Named class CdiBean implements Converter { @EJB ... }
Fails with 'Default behavior invoked of requiring a converter-id passed in the constructor'
Anyhow first approach using binding and app scoped JSF bean works.
回答3:
The Seam Faces extension for JSF 2.0 and CDI allows @Inject support directly in Validators and Converters.
Check it out: http://ocpsoft.com/java/seam-faces-3-0-0-alpha2-jsf-2-0-just-got-even-easier/
回答4:
i don't know if this solution is pretty... but it does work:
@ManagedBean
public class AcquisitionConverter implements Converter
{
@EJB
private AcquisitionService service;
@Override
public Object getAsObject(FacesContext context, UIComponent component, String value)
{
...
}
@Override
public String getAsString(FacesContext context, UIComponent component, Object value)
{
...
}
}
and
<h:inputText value="#{flowController.acquisition}" converter="#{acquisitionConverter}">
with jsf 2.1.3 (mojarra) and glassfish 3.1.1
来源：https://stackoverflow.com/questions/2019495/inject-a-ejb-into-a-jsf-converter-with-jee6