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#Inject annotation not working

I'm trying to use CDI for the first time. While I have successfully injected one EJB inside another using #EJB, I can't get the #Inject annotation to work.
#Stateless
public class AccountDaoImpl implements AccountDAO {
#Inject
private MultiTenantEntityManagerImpl mtem; //always null
}
And the multi-tenancy entity manager looks like this:
#Default
public class MultiTenantEntityManagerImpl {
.....
}
I've created a beans.xml file (empty) but and shoehorned it into the META-INF folder in the built jar file. Still no joy.
I'm sure it's something simple. I'm running in jboss 5.0.1.GA.
Update
So it looks like the #Inject annotation is not supported in jboss 5.
An alternative is to use the #EJB annotation, but this isn't working either:
#Stateless
public class AccountDaoImpl implements AccountDAO {
#EJB
private MultiTenantEntityManager mtem; //still null!
}
Weirdly, in another EJB, this exact declaration of the entity manager is working fine.

in my case i was missing subsystem in the standalone

It looks like, in jboss 5 at least, an #EJB annotation will only be respected if both the following conditions hold:
The class in which you're using it is an EJB
The class is retrieved from the container somehow (eg JNDI), rather than being simply instantiated via a constructor.

EJB injection into non managed objects

we are upgrading our web application to Oracle WebLogic 12c with EJB 3.x, and we got an issue.
This is the scenario...
We have a simple EJBs that we are going to call MyService, defined with its bean and local/remote interfaces defined by the EJB 3.x annotations.
Here is a pseudo code of the scenario:
class MyListener implements ServletContextListener {
#EJB private MyService myService;
public void contextInitialized(ServletContextEvent arg0) {
// Here myService is correctly instantiated, so we do something...
}
}
Now we have to move the contextInitialized method logic inside an utility class, so the new scenario will be:
class MyUtility {
#EJB private MyService myService;
public void doSomething() {
// Here myService is NULL!!!!!
}
}
class MyListener implements ServletContextListener {
public void contextInitialized(ServletContextEvent arg0) {
new MyUtility().doSomething();
}
}
I have read a lot of documentation about that problem, and I discovered that only some kind of classes are scanned by the Application Server to resolve the injected EJBs ( Java EE 6, 5, 7 | List of managed beans or classes: EJBs , JSF beans and ..? ).
Is there a workaround to force the scanning of a custom class like mine with WebLogic?
Thank you very much.

There is an option to wrap you Injection into a CDI-Component and to use this one in your code. CDI has the capability to work in standalone java, as soon as you configured it well.
Another helpful option can be the fact, that CDI supports EJB-injection too (in some usecases):
CDI.current().select(MyService.class).get();
BUT: EJBs has their own Transaction-Management. So I would prefer the wrapping into a cdi-component to get more controll in it.

JAX-RS Application subclass injection

I'm writing custom JAX-RS 2.0 application (under Jersey 2.3.1) which holds some data for use by all the resources.
public class WebApp extends org.glassfish.jersey.server.ResourceConfig {
public WebApp() {
packages("my.resources.package");
}
}
(I could use API's javax.ws.rs.core.Application as well, the described result is the same)
Then I inject the object into a resource
#Path("test")
public class Test {
#Context
Application app;
#GET
#Path("test")
public String test() {
return "Application class: " + app.getClass();
}
}
However, the result of a call is
Application class: class org.glassfish.jersey.server.ResourceConfig$WrappingResourceConfig
which makes me use some ugly tricks like
if (app instanceof WebApp) {
return (WebApp) app;
} else if (app instanceof ResourceConfig) {
return (WebApp) ((ResourceConfig) app).getApplication();
}
My understanding of JAX-RS 2.0 spec section 9.2.1:
The instance of the application-supplied Application subclass can be injected into a class field or method parameter using the #Context annotation. Access to the Application subclass instance allows configuration information to be centralized in that class. Note that this cannot be injected into the Application subclass itself since this would create a circular dependency.
is that application-supplied Application subclass is mine WebApp, not JAX-RS implementation-specific wrapper.
Also, changing this fragment
#Context
Application app;
to this
#Context
WebApp app;
causes app to be null, due to ClassCastException during context injection, so the declared type doesn't matter.
Is it a bug in Jersey or my misunderstanding?
UPDATE: I checked the behaviour under RESTEasy 3.0. The injected object is my WebApp, without any wrappers. I'd call it a bug in Jersey.

This doesn't seem like a bug. According to JAX-RS 2.0 spec you can inject Application into your resource classes (for example) but it does not say anything about directly injecting custom extensions of the Application. Not sure what your use-case is but you can register custom HK2 binder that will allow you to inject directly WebApp into resources:
public class WebApp extends org.glassfish.jersey.server.ResourceConfig {
public WebApp() {
packages("my.resources.package");
register(new org.glassfish.hk2.utilities.binding.AbstractBinder() {
#Override
protected void configure() {
bind(WebApp.this);
}
});
}
}

I too have encountered this using Jersey 2.4.1.
FWIW: I agree it seems like a bug according to the spec para 8.2.1. The statement "The instance of the application-supplied Application subclass" seems perfectly clear.
I have an alternative workaround that doesn't involve glassfish.hk2 but still concentrates the Jersey-specific code in the Application-derived class.
public class MyApp extends ResourceConfig {
...
static MyApp getInstance( Application application) {
try {
// for a conformant implementation
return (MyApp) application;
} catch (ClassCastException e) {
// Jersey 2.4.1 workaround
ResourceConfig rc = (ResourceConfig) application;
return (MyApp) rc.getApplication();
}
}
...
}
public class MyResource {
...
#Context Application application;
...
SomeMethod() {
... MyApp.getInstance( application);
}
}
Hope this is useful.

This appears to be fixed in a later version og Jersey. The same approach works for me with Jersey 2.16 at least. My injected Application object is of the correct subclass without any wrapping whatsoever.
Edit: Or maybe the version is irrelevant after all. Please see the comments to this answer.

How to inject one EJB 3.1 into another EJB

I'm developping simple app where one EJB should be injected into another. I'm developping in IDEA Jetbrains IDE. But after i make #EJB annotation in Ejb local statless class my IDE highlight it with error:
EJB '' with component interface 'ApplicationController' not found.
Can anyone tell Why?

Injection of an EJB reference into another EJB can be done using the #EJB annotation. Here is an example taken from Injection of other EJBs Example from the OpenEJB documentation:
The Code
In this example we develop two simple
session stateless beans (DataReader
and DataStore), and show how we can
use the #EJB annotation in one of
these beans to get the reference to
the other session bean
DataStore session bean
Bean
#Stateless
public class DataStoreImpl implements DataStoreLocal, DataStoreRemote{
public String getData() {
return "42";
}
}
Local business interface
#Local
public interface DataStoreLocal {
public String getData();
}
Remote business interface
#Remote
public interface DataStoreRemote {
public String getData();
}
DataReader session bean
Bean
#Stateless
public class DataReaderImpl implements DataReaderLocal, DataReaderRemote {
#EJB private DataStoreRemote dataStoreRemote;
#EJB private DataStoreLocal dataStoreLocal;
public String readDataFromLocalStore() {
return "LOCAL:"+dataStoreLocal.getData();
}
public String readDataFromRemoteStore() {
return "REMOTE:"+dataStoreRemote.getData();
}
}
Note the usage of the #EJB annotation
on the DataStoreRemote and
DataStoreLocal fields. This is the
minimum required for EJB ref
resolution. If you have two beans that
implement the same business
interfaces, you'll want to the
beanName attribute as follows:
#EJB(beanName = "DataStoreImpl")
private DataStoreRemote dataStoreRemote;
#EJB(beanName = "DataStoreImpl")
private DataStoreLocal dataStoreLocal;
Local business interface
#Local
public interface DataReaderLocal {
public String readDataFromLocalStore();
public String readDataFromRemoteStore();
}
(The remote business interface is not
shown for the sake of brevity).
If it doesn't work as expected, maybe show some code.

I believe it's an IntelliJ IDEA bug. This thread solved the problem for me:
adding a EJB Facet (in project structure > modules) helped

Inject an EJB into JAX-RS (RESTful service)

I'm trying to inject a Stateless EJB into my JAX-RS webservice via annotations. Unfortunately the EJB is just null and I get a NullPointerException when I try to use it.
#Path("book")
public class BookResource {
#EJB
private BookEJB bookEJB;
public BookResource() {
}
#GET
#Produces("application/xml")
#Path("/{bookId}")
public Book getBookById(#PathParam("bookId") Integer id)
{
return bookEJB.findById(id);
}
}
What am I doing wrong?
Here is some information about my machine:
Glassfish 3.1
Netbeans 6.9 RC 2
Java EE 6
Can you guys show some working example?

I am not sure this is supposed to work. So either:
Option 1: Use the injection provider SPI
Implement a provider that will do the lookup and inject the EJB. See:
#EJB injection.
Example for com.sun.jersey:jersey-server:1.17 :
import com.sun.jersey.core.spi.component.ComponentContext;
import com.sun.jersey.core.spi.component.ComponentScope;
import com.sun.jersey.spi.inject.Injectable;
import com.sun.jersey.spi.inject.InjectableProvider;
import javax.ejb.EJB;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.ws.rs.ext.Provider;
import java.lang.reflect.Type;
/**
* JAX-RS EJB Injection provider.
*/
#Provider
public class EJBProvider implements InjectableProvider<EJB, Type> {
public ComponentScope getScope() {
return ComponentScope.Singleton;
}
public Injectable getInjectable(ComponentContext cc, EJB ejb, Type t) {
if (!(t instanceof Class)) return null;
try {
Class c = (Class)t;
Context ic = new InitialContext();
final Object o = ic.lookup(c.getName());
return new Injectable<Object>() {
public Object getValue() {
return o;
}
};
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
Option 2: Make the BookResource an EJB
#Stateless
#Path("book")
public class BookResource {
#EJB
private BookEJB bookEJB;
//...
}
See:
How to Combine REST Services with EJB 3.1
EJB 3.1 And REST - The Lightweight Hybrid
Option 3: Use CDI
#Path("book")
#RequestScoped
public class BookResource {
#Inject
private BookEJB bookEJB;
//...
}
See:
Injecting an EJB from a jar into a jax-rs class in a war

This thread is rather old, nevertheless i fought the same problem just yesterday. Here is my solution:
Just make the BookResource a managed bean through #javax.annotation.ManagedBean at class level.
For this to work you need to enable CDI with a beans.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
</beans>
This file needs to be in WEB-INF if the BookResource is part of a war file. If the BookResource is packaged with the ejbs put it into META-INF.
If you want to use #EJB you're done. If you want to inject the EJB through #Inject than a beans.xml must be put into the ejbs jar file into META-INF as well.
What you're doing: You're just telling the container that the resource should be container managed. Therefor it supports injection as well as lifecycle events. So you have your business facade without promoting it to an EJB.
You don't need to extend javax.ws.rs.core.Application for this to work. BookResource is as a root resource automatically request scoped.
Tested with Glassfish 3.1.2 and a maven project.
Happy coding.

You shall be able to do injection in JAX-RS resource without making it EJB or CDI component. But you have to remember that your JAX-RS resource must not be singleton.
So, you setup your application with this code. This makes BookResource class per-request JAX-RS resource.
#javax.ws.rs.ApplicationPath("application")
public class InjectionApplication extends javax.ws.rs.core.Application {
private Set<Object> singletons = new HashSet<Object>();
private Set<Class<?>> classes = new HashSet<Class<?>>();
public InjectionApplication() {
// no instance is created, just class is listed
classes.add(BookResource.class);
}
#Override
public Set<Class<?>> getClasses() {
return classes;
}
#Override
public Set<Object> getSingletons() {
return singletons;
}
}
With this setup, you are letting JAX-RS to instantiate BookResource for you on per-request basis and also inject all the required dependencies. If you make BookResource class singleton JAX-RS resource, this is, you put in getSingletons
public Set<Object> getSingletons() {
singletons.add(new BookResource());
return singletons;
}
then, you created instance which is not managed by JAX-RS runtime and nobody in container cares to inject anything.

Unfortunately, my answer is too long for a comment, so here goes. :)
Zeck, I hope that you are aware of what exactly you are doing by promoting your bean to an EJB, as suggested by Pascal. Unfortunately, as easy as it is nowadays with Java EE to 'make a class an EJB', you should be aware of the implications of doing so. Each EJB creates overhead along with the additional functionality it provides: they are transaction aware, have their own contexts, they take part in the full EJB life cycle, etc.
What I think you should be doing for a clean and reusable approach is this: extract the access to your servers services (which hopefully are accessed through a SessionFacade :) into a BusinessDelegate. This delegate should be using some kind of JNDI lookup (probably a ServiceLocator - yes, they are still valid in Java EE!) to access your backend.
Okay, off the record: if you really, really, really need the injection because you do not want to write JNDI access manually, you could still make your delegate an EJB, although it ... well, it just feels wrong. :)
That way at least it will be easy to replace it later with something else if you do decide to switch to a JNDI lookup approach...

I was trying to do the exact same thing. I'm using EJB 3.1 and have a deployed my app as an EAR with separate EJB project. As Jav_Rock pointed out, I use context lookup.
#Path("book")
public class BookResource {
#EJB
BookEJB bookEJB;
public BookResource() {
try {
String lookupName = "java:global/my_app/my_ejb_module/BookEJB";
bookEJB = (BookEJB) InitialContext.doLookup(lookupName);
} catch (NamingException e) {
e.printStackTrace();
}
}
#GET
#Produces("application/xml")
#Path("/{bookId}")
public Book getBookById(#PathParam("bookId") Integer id) {
return bookEJB.findById(id);
}
}
See the link below for very useful JNDI look up tips
JNDI look up tips

Arjan is right. I created another class to initialize the EJB instead of creating a bean for RS
#Singleton
#LocalBean
public class Mediator {
#EJB
DatabaseInterface databaseFacade;
to avoid null pointer with:
#Path("stock")
public class StockResource {
#EJB
DatabaseInterface databaseFacade;
...
it actually works on GF

I have the same problem, and I solved it calling te EJB by a context lookup (the injection was impossible, I had the same error NullPointerException).