Comments on: Getting Started with CDI part 2 – Injection

By: Bernard

Bernard — Thu, 03 Mar 2011 13:20:07 +0000

Hi Andy
I am trying – without success – to inject a PersistenceContext (using @PersistenceContext) in DAO’s:

//@ManagedBean
public class JpaItemDao implements ItemDao {

@PersistenceContext(unitName=”myUnit”)
private EntityManager em;

public List fetchItems() {
// use em to retrieve from db
}
}

But is does not work (em is not set), even with the addition of javax.annotation.ManagedBean…
(running in GF 3.1)

Do you think it is possible ?
Could be use @Inject isof @PersistenceContext ?

Regards,

Bernard, Belgium
(running in GlassFish 3.1)

By: Andy Gibson

Andy Gibson — Mon, 17 Jan 2011 05:46:04 +0000

Can’t really tell what the problem is but It looks like you are trying to inject a remote session bean which can’t be done directly in CDI. To do so, you need to inject the EJB using @EJB and then push that out using produced. I’ve never done it, but it should look something like :

@EJB({params}) @Produces
private MyBean myBean;

This code goes in some utility or factory bean. In your business logic bean, you can then use :

@Inject private MyBean myBean;

The injection point will use the producer to provide the value to the injection point. Again, I’ve not tried this and this code is off the top of my head. Search the web for CDI and remote beans or consult the 299 spec to get a better idea if this is your problem.

Cheers,

Andy Gibson

By: Waltenio

Waltenio — Sun, 16 Jan 2011 19:29:30 +0000

Dear Andy,

How can I fix this error?

An Error Occurred:
Um erro ocorreu ao realizar a inje??o de recurso no bean gerenciado emprestimoController
+- Stack Trace

com.sun.faces.mgbean.ManagedBeanCreationException: Um erro ocorreu ao realizar a inje??o de recurso no bean gerenciado emprestimoController
at com.sun.faces.mgbean.BeanBuilder.injectResources(BeanBuilder.java:211)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:405)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:267)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:86)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:175)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:99)
at com.sun.el.parser.AstValue.getValue(AstValue.java:158)
at com.sun.el.parser.AstEqual.getValue(AstEqual.java:54)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:71)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:102)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:190)
at javax.faces.component.UIComponentBase.isRendered(UIComponentBase.java:416)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1607)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:848)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1613)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:273)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57)
at com.sun.grizzly.ContextTask.run(ContextTask.java:69)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309)
at java.lang.Thread.run(Thread.java:662)
Caused by: com.sun.faces.spi.InjectionProviderException: com.sun.enterprise.container.common.spi.util.InjectionException: Exception attempting to inject Remote ejb-ref name=jpa.entities.EmprestimoController/ejbFacade,Remote 3.x interface =jpa.entities.EmprestimoFacade,ejb-link=null,lookup=null,mappedName=,jndi-name=jpa.entities.EmprestimoFacade,refType=Session into class jpa.entities.EmprestimoController
at org.glassfish.faces.integration.GlassFishInjectionProvider.inject(GlassFishInjectionProvider.java:98)
at com.sun.faces.mgbean.BeanBuilder.injectResources(BeanBuilder.java:205)
… 51 more
Caused by: com.sun.enterprise.container.common.spi.util.InjectionException: Exception attempting to inject Remote ejb-ref name=jpa.entities.EmprestimoController/ejbFacade,Remote 3.x interface =jpa.entities.EmprestimoFacade,ejb-link=null,lookup=null,mappedName=,jndi-name=jpa.entities.EmprestimoFacade,refType=Session into class jpa.entities.EmprestimoController
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:614)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.inject(InjectionManagerImpl.java:384)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:168)
at org.glassfish.faces.integration.GlassFishInjectionProvider.inject(GlassFishInjectionProvider.java:94)
… 52 more
Caused by: javax.naming.NamingException: Lookup failed for ‘java:comp/env/jpa.entities.EmprestimoController/ejbFacade’ in SerialContext [Root exception is javax.naming.NamingException: Exception resolving Ejb for 'Remote ejb-ref name=jpa.entities.EmprestimoController/ejbFacade,Remote 3.x interface =jpa.entities.EmprestimoFacade,ejb-link=null,lookup=null,mappedName=,jndi-name=jpa.entities.EmprestimoFacade,refType=Session' . Actual (possibly internal) Remote JNDI name used for lookup is 'jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade' [Root exception is javax.naming.NamingException: Lookup failed for 'jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade' in SerialContext [Root exception is javax.naming.NameNotFoundException: jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade not found]]]
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:442)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:513)
… 55 more
Caused by: javax.naming.NamingException: Exception resolving Ejb for ‘Remote ejb-ref name=jpa.entities.EmprestimoController/ejbFacade,Remote 3.x interface =jpa.entities.EmprestimoFacade,ejb-link=null,lookup=null,mappedName=,jndi-name=jpa.entities.EmprestimoFacade,refType=Session’ . Actual (possibly internal) Remote JNDI name used for lookup is ‘jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade’ [Root exception is javax.naming.NamingException: Lookup failed for 'jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade' in SerialContext [Root exception is javax.naming.NameNotFoundException: jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade not found]]
at com.sun.ejb.EjbNamingReferenceManagerImpl.resolveEjbReference(EjbNamingReferenceManagerImpl.java:174)
at com.sun.enterprise.container.common.impl.ComponentEnvManagerImpl$EjbReferenceProxy.create(ComponentEnvManagerImpl.java:1040)
at com.sun.enterprise.naming.impl.GlassfishNamingManagerImpl.lookup(GlassfishNamingManagerImpl.java:688)
at com.sun.enterprise.naming.impl.GlassfishNamingManagerImpl.lookup(GlassfishNamingManagerImpl.java:657)
at com.sun.enterprise.naming.impl.JavaURLContext.lookup(JavaURLContext.java:148)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:428)
… 57 more
Caused by: javax.naming.NamingException: Lookup failed for ‘jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade’ in SerialContext [Root exception is javax.naming.NameNotFoundException: jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade not found]
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:442)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at com.sun.ejb.EjbNamingReferenceManagerImpl.resolveEjbReference(EjbNamingReferenceManagerImpl.java:169)
… 62 more
Caused by: javax.naming.NameNotFoundException: jpa.entities.EmprestimoFacade#jpa.entities.EmprestimoFacade not found
at com.sun.enterprise.naming.impl.TransientContext.doLookup(TransientContext.java:197)
at com.sun.enterprise.naming.impl.TransientContext.lookup(TransientContext.java:168)
at com.sun.enterprise.naming.impl.SerialContextProviderImpl.lookup(SerialContextProviderImpl.java:58)
at com.sun.enterprise.naming.impl.LocalSerialContextProviderImpl.lookup(LocalSerialContextProviderImpl.java:101)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:430)
… 64 more

By: Andy Gibson

Andy Gibson — Fri, 16 Jul 2010 22:55:23 +0000

You might also want to try out a set of Maven Archetypes I just released which in addition contains the usual starter projects, also has a project that implements a CRUD demo with just out-of-the-box Java EE 6.

You can find it at http://www.fluttercode.com/projects/knappsack/

By: Andy Gibson

Andy Gibson — Fri, 16 Jul 2010 22:53:12 +0000

Hey Herman,

Both type and and Qualifiers are used to match beans to injection points so a qualifier is just an additional criteria in case you have beans that implement the same interface.

For example, if you have multiple data source and inject the entity manager, you could qualify one with @WebStoreDb and the other with @DataWarehouseDb. Without a qualifier, we don’t know which to use where.

By: Herman Chung

Herman Chung — Fri, 16 Jul 2010 17:08:16 +0000

Btw, Thanks Andy for this article, it is very informative and easy to understand, i was having a hard time learning just by reading the Weld Docs

By: Herman Chung

Herman Chung — Fri, 16 Jul 2010 17:07:08 +0000

Maybe I am just confused or that I am very new to CDI, so the advantage of Qualifier is that it is typesafe (can apply to interface instead of using names which only applies to implementation)..

so we basically need to create multiple qualifers (meaning multiple classes) for each implementations of the interface we might want to inject?

This does seem kinda inconvenient..

By: Getting Started with Netbeans, JSF 2.0 and CDI part 1 | FlutterCode

Getting Started with Netbeans, JSF 2.0 and CDI part 1 | FlutterCode — Sun, 16 May 2010 03:06:24 +0000

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By: Robert, Austin, Texas

Robert, Austin, Texas — Sat, 10 Apr 2010 04:51:13 +0000

Thanks for the reply. Nope, it is not annotated @Stateless. Until I changed the bean to SessionScope I was copying and pasting from your examples, too. Go figure…

By: Andy Gibson

Andy Gibson — Fri, 09 Apr 2010 04:10:17 +0000

Is the item processor a stateless bean? If so, take off the @Stateless annotation. There is a problem with Weld 1.0 (and maybe 1.0.1) where stateless beans were considered not proxyable which is wrong because they don’t need to be proxied :

Here’s my post about it on the seam framework web site.

http://seamframework.org/Community/ProblemsWithStatelessBeansInWeldCR101CR2

You should be ok if you just remove the stateless annotation making it a non-EJB bean

Cheers,

Andy Gibson