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I am trying to inject an entity manager in a DAO class and test it, using weld container, but i keep getting the following exception:

org.jboss.weld.exceptions.NullInstanceException: WELD-000044 Unable to obtain instance from org.jboss.weld.bean-se-module-ProducerField-com.playground.cdi_tutorial.beans.Resources.em at org.jboss.weld.bean.builtin.CallableMethodHandler.invoke(CallableMethodHandler.java:60) at org.jboss.weld.util.CleanableMethodHandler.invoke(CleanableMethodHandler.java:43) at javax.persistence.EntityManager_$$_javassist_2.createQuery(EntityManager_$$_javassist_2.java) at com.playground.cdi_tutorial.model.EventDAO.getAllEvents(EventDAO.java:22) at com.playground.cdi_tutorial.beans.ValidationService.validateEvenNumbers(ValidationService.java:23) at com.playground.cdi_tutorial.beans.MyFactory.sayHi(MyFactory.java:15) at com.playground.cdi_tutorial.beans.MyFactoryTest.should_say_bye(MyFactoryTest.java:26) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184) at org.junit.runners.ParentRunner.run(ParentRunner.java:236) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

I try to inject the entity manager as follows:

 @Inject
 @EmProducer
 EntityManager em;

where EmProducer looks like this:

@Qualifier
@Target({ TYPE, METHOD, PARAMETER, FIELD })
@Retention(RUNTIME)
@Documented
public @interface EmProducer {

    public static final String UNIT_NAME = "cdi-tutorial";

}

And the producer class looks like this:

public class Resources {

 @Produces
 @EmProducer
 @PersistenceContext(unitName = EmProducer.UNIT_NAME)
 private EntityManager em;
       ...
    }

In my test, when this line of code is hit Query q = em.createQuery("from Employee"); I get the exception above. The entity manager, em, is not null though.

PS: I use WeldJUnit4Runner (http://www.hostettler.net/blog/2012/04/02/how-to-test-a-jsf-named-bean/) to run my tests.

I would really appreciate your help.

Thanks!

Maria
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1 Answers1

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I would suggest using Arquillian for this kind of test. It makes in-container tests really easy (and fast). You can just inject EntityManager normally and Arquillian takes care of the rest...

turgayze
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  • Thanks, but that's exactly what I want to avoid. I don't need all the services offered by an application server, I just need to be able to inject managed beans, including the entity manager itself. I think the problem is related to the fact that @PersistenceContext annotation is not 'recognized' by Weld Container. I'll try using another Producer, by creating the EntityManager with the help of EntityManagerFactory. – Maria Nov 14 '12 at 09:20
  • OK, but just give it a try for Arquillian when you have time. Tests run really fast, you can deploy to a running server(remote) or start and stop the server in the test(managed). There is a tutorial for testing persistence at: http://arquillian.org/guides/testing_java_persistence/ About starting all services, if you are using Glassfish or JBoss, they start really fast because the don't load unused services. – turgayze Nov 14 '12 at 09:42