WELD-000049: Unable to invoke void com.mydomain.bc.alert.AService.init() Caused by java.lang.NullPointerException

[brucespringfield]

Trying to inject dependencies into a Junit test with Weld. But Weld is getting a NullPointer Exception 

Caused by: java.lang.reflect.InvocationTargetException

  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

  at java.lang.reflect.Method.invoke(Method.java:497)

  at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.invokeMethods(DefaultLifecycleCallbackInvoker.java:98)

  ... 51 more

Caused by: java.lang.NullPointerException

  at com.mydomain.bc.configuration.facade.AConfigurationFacadeImpl.getInputContactOfMyD(AConfigurationFacadeImpl.java:36)

  at com.mydomain.bc.alert.AService.initAContactCache(AService.java:87)

  at com.mydomain.bc.alert.AService.init(AService.java:83)

  ... 56 more

It seems Weld has a problem injecting the nested dependency of the first dependency.

Is there a workaround for this problem?

1)

@Singleton

@LocalBean

public class OuterEventObserverBCAC extends OuterEventObserver {

.

.

.

@Inject

private AService aService;

}

2)

@Singleton

@Startup

@LocalBean

public class AService {

.

.

.

@Inject

private ACRepository acRepository;

}

3)

@ApplicationScoped

@Singleton

public class ACRepository extends RRepositoryImpl<AContact> {

.

.

.

4)

    @Inject

    @AContactCache

    private RCache<String, AContact> alCCache;

}

[mkouba]

Bruce, it seems the NullPointerException is thrown from the application code: com.mydomain.bc.configuration.facade.AConfigurationFacadeImpl.getInputContactOfMyD(AConfigurationFacadeImpl.java:36)

[brucespringfield]

Yes, but the Exception only occurs when I try to inject dependencies into the test with Weld. If I don't do this, this Exception doesn't occur.

[mkouba]

I'm afraid we can't help you without a deeper knowledge of the source code. E.g. it's very important to know what's on the line AConfigurationFacadeImpl.java:36.

[brucespringfield]

On line 36 of AConfigurationFacadeImpl:

return configurationService.getMsr().getMsrD().stream() //

.filter(dep -> isDOfNtip(dep))//

.flatMap(asStream(MsrD::getMsrAudioFv)) //

.flatMap(asStream(MsrAudioFv::getMsrInputContact));

It seems the injected Bean is not using configurationService.

The injected bean is:

OuterEventObserverBCAC

It is being injected into the test through:

private static void initializeCdiDependencies() {

  cdiContainer = CdiContainer.getInstance();

  cdiContainer.initializeCdiContainer();

  outerEventObserverBCAC = cdiContainer.getBean(outerEventObserverBCAC.class);

  cdiContainer.shutdownCdiContainer();

}

The error starts at the line:

  outerEventObserverBCAC = cdiContainer.getBean(outerEventObserverBCAC.class);

configurationService is not injected. Should it be injected also?

My cdiContainder code:

public final class CdiContainer {

    private static final CdiContainer INSTANCE = new CdiContainer();

    /** The logger for CdiContainer. */

    // private final static Logger LOG = LogManager.getLogger(CdiContainer.class);

    /**

    * Get the current instance of the CdiContainer to obtain managed beans.

    *

    * @return the {@link CdiContainer}.

    */

    public static final CdiContainer getInstance() {

      return INSTANCE;

    }

    /**

    * Constructor.

    */

    private CdiContainer() {

    }

    /**

    * Obtain the managed bean of the provided type from the CDI container.

    *

    * @param clazz

    *            the type of the bean to get from the CDI container.

    * @param qualifiers

    *            the qualifiers for the bean selection to resolve ambiguous beans.

    * @return the managed bean instance.

    */

    public <T> T getBean(final Class<T> clazz, final Annotation... qualifiers) {

          return weldContainer.select(clazz, qualifiers).get();

    }

    /**

    * Initialize the CDI container. Must be only called once during application startup.

    */

    public void initializeCdiContainer() {

      if (weldContainer == null) {

          // LOG.debug("Initializing CDI implementation JBoss Weld");

          // Initialize the CDI reference implementation JBoss WELD to bootstrap CDI and get access to managed beans

          final Weld weld = new Weld();

          weldContainer = weld.initialize();

      } else {

          // LOG.debug("JBoss Weld already initialized");

      }

  }

  public void shutdownCdiContainer() {

      if (weldContainer != null) {

        weldContainer.shutdown();

      }

  }

    /** The weld container controlling the life cycle of all CDI managed beans. */

    public WeldContainer weldContainer;

}

[brucespringfield]

The solution was not to inject dependencies into a Junit test with Weld. I was trying to use the WeldContainer to inject the dependencies. But there were too many nested and complex dependencies to make it realistic. I kept getting NullPointer Exceptions everywhere. So instead of using Weld and the WeldContainer, I scrapped it and used CdiRunner to run the Junit test. CdiRunner works very well injecting dependencies. It was important to use the @AdditionalClasses and @ActivatedAlternatives annotations to let CdiRunner know which classes needed to be injected. One trick was to add the test class itself into the @ActivatedAlternatives annotation.

Here is a sample:

@Alternative

@RunWith(CdiRunner.class)

@AdditionalClasses({ ACFacadeImpl.class })

@ActivatedAlternatives({ ACServiceNonArqBCT.class, MshoEventObserverBcACFake.class })

public class ACServiceNonArqBCT {

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.

.