Injection of Simple Environment Entry into Session Bean Using @Resource Annotation

[bafco]

Hi,

I'm having a rough time using @Resource annotation to inject a String into a session bean.
Deployment archive structure:
test.war
- web.xml
- beans.xml
- lib/...
- classes/...
I have the following class (in 'classes' folder):

import javax.annotation.Resource;
import javax.ejb.Stateless;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

@Stateless
public class Bar {
    @Resource(lookup = "java:app/env/greeting")
    public String greeting;

    public String lookup() throws NamingException {
        Context initCtx = new InitialContext();
        return (String) initCtx.lookup("java:app/env/greeting");
    }
}

The web.xml looks like this:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="3.0" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
  <env-entry>
    <env-entry-name>java:app/env/greeting</env-entry-name>
    <env-entry-type>java.lang.String</env-entry-type>
    <env-entry-value>Hello</env-entry-value>
  </env-entry>
</web-app>

The problem is, for 'bar' - created instance of Bar - it holds that bar.greeting == null. However, bar.lookup().equals("Hello");

I tried to instantiate the Bar instance using @EJB injection, using javax.inject.Provider.get() method of injected javax.enterprise.inject.Instance<Bar> instance, using BeanManager and CreationalContext, but the result is still the same.

Making the Bar class Statefull, using the "java:comp/env" context or declaring the env-entry in ejb.jar.xml doesn't help to solve the problem.

What am I doing wrong?

I am using: Wildfly version: 8.0.0.Beta1, Weld version: 2.1.0.Final.

[sfcoy]

What happens if you change the web.xml to:

<env-entry-name>greeting</env-entry-name>

and the java code to:

@Resource(name = "greeting")

?

[bafco]

The result is the same, greeting == null. I gave up on using @Resource.name() in session bean classes as it somehow doesn't seem to work at all. (However, it works great on CDI managed beans.)

[sfcoy]

Actually, I suspect that env-entry elements in a web.xml will not be picked up by EJBs. You probably need to add then to an ejb-jar.xml file.

[bafco]

As I stated before, declaring the env-entry in ejb-jar.xml doesn't help to solve the problem. It works the same way as web.xml, i.e. it doesn't work.

Here is my WEB-INF/ejb-jar.xml for the @Resource(name = greeting) version:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ejb-jar xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" metadata-complete="false" version="3.1" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/ejb-jar_3_1.xsd">
  <enterprise-beans>
    <session>
      <ejb-name>Bar</ejb-name>
      <session-type>Stateless</session-type>
      <env-entry>
        <env-entry-name>greeting</env-entry-name>
        <env-entry-type>java.lang.String</env-entry-type>
        <env-entry-value>Hello</env-entry-value>
      </env-entry>
    </session>
  </enterprise-beans>
</ejb-jar>

I also tried @Resource(lookup = ...) with names 'java:app/env/greeting' and 'java:comp/env/greeting'.

Everything seems to be the same, e.g. Context.lookup() works just fine and returns the correct string.

Anyway, I can't find anything in any specification indicating that env-entries in web.xml might be "ignored" by EJBs.

I consider this a bug; unless someone can successfully inject values of env-entries defined in a deployment descriptor using @Resource into a session bean, all in a war file (implying that I've made a mistake somewhere.)

[jaikiran]

This should have worked. Let me take a look. We have had recent changes in this area and it's possible that we might have introduced a bug.

[sfcoy]

I think this is missing a

<ejb-class>...</ejb-class>

element.

[bafco]

Yep, I tried this trick before, but did not work either. I added

<ejb-class>org.jboss.cdi.tck.interceptors.tests.contract.interceptorLifeCycle.jndi.ejb.Bar</ejb-class>

under <ejb-name> element in ejb-jar.xml, as Bar's package is org.jboss.cdi.tck.interceptors.tests.contract.interceptorLifeCycle.jndi.ejb.

[sfcoy]

I just tried this out on a WildFly 8.0 Beta1 SNAPSHOT and it works for me using the env-entry from the web.xml.

<env-entry>
  <env-entry-name>testRef</env-entry-name>
  <env-entry-type>java.lang.String</env-entry-type>
  <env-entry-value>Foo bar</env-entry-value>
</env-entry>

and

@Stateless
public class MemberRegistration {


    @Inject
    private Logger log;


    @Inject
    private EntityManager em;


    @Inject
    private Event<Member> memberEventSrc;


    @Resource(name="testRef")
    private String sampleEnvRef;
  
    @PostConstruct
    void testEnvRef() {
       log.info("Installed env ref sampleEnvRef = '" + sampleEnvRef + "'");
    }
  
    public void register(Member member) throws Exception {
        log.info("Registering " + member.getName());
        em.persist(member);
        memberEventSrc.fire(member);
    }
}

giving:

21:17:19,827 INFO  [org.jboss.demos.forum2210.envrefdemo.service.MemberRegistration] (default task-15) Installed env ref sampleEnvRef = 'Foo bar'

I'll try it out with a beta2 snapshot shortly

[sfcoy]

This code also works in a wildfly-8.0.0.Beta2-SNAPSHOT fwiw.

In addition, I tried changing the env-entry-name to java:global/testRef and the @Resource name to "java:global/testRef" and that works too.

You must have something else going wrong.

[bafco]

How do you create a MemberRegistration instance?

[sfcoy]

The container creates it. Instances of it are injected into a number of other CDI beans.

It's (based on) sample code from https://github.com/jboss-jdf/jboss-as-quickstart/.

You will never get injection working on objects that you create yourself using "new".

[bafco]

Actually, the problem was that I was accessing session bean's field from outside the class. That is why I got bar.greeting == null;, injection works just fine.

Thank you both for your help and effort. Jaikiran's tests in WF testsuite helped me solve the problem