Re: [weld-dev] @Resource annotation handling by Weld vs Servlet container

Jozef, >> Looking at the WeldServletLifecyle class on line 124, it will always >> provide an implementation of the ResourceInjectionServices (an >> instance of ServletResourceInjectionServices). If we were to provide >> our own implementation of ResourceInjectionServices, how would we >> override that one? Is there a way to get a hold of the Deployment and >> thus the BeanDeploymentArchives so we could set our own implementation >> up? Ideally we'd like a pure CDI api way of interacting with weld, but >> maybe that's not possible in this case? > You need to interact with Weld APIs to do this. A service can be overridden > using ServiceLoader mechanism. See > http://docs.jboss.org/weld/reference/2.2.10.Final/en-US/html/ri-spi.html#... > for details. Ok, great, I'll give this a go and report back.

>> Alternatively, instead of Weld >>> hooking into lifecycle of Jetty-managed components, Jetty could use CDI >>> APIs >>> to perform CDI injection on instances it manages. >>> >> Yes, potentially we could do that, although we'd probably need your >> guidance on the best way to do that. Can @Resource be used by pojo >> beans or only by servlet artifacts (servlet/filter/listeners)? If the >> latter, then I'm fine for Jetty to do all the handling of @Resource. >> If not, then it probably makes sense for weld to handle it, and we'd >> need a way to disable Jetty's implementation if weld is present in a >> webapp ... > I think the best approach would be to modify the integrating decorator to > only provide CDI injection to Jetty-managed instances. I have implemented it > here: > https://github.com/weld/core/commit/f7420e34355c5c82ef516713c65fc6cd750fb651 So if jetty is handling @Resource (handling making the jndi entries and injecting the fields/methods) for servlets/filters/listeners, what will happen if someone declares this in eg a servlet: public class MyServlet extends HttpServlet { @Producer @Resource (name="foo") @MyDb private DataSource db; } Will weld still inspect this class and find the producer and make it available for injection in other code?

cheers Jan >> cheers >> Jan >> >>> Additional comments inline: >>> >>> >>> On 04/10/2015 02:00 AM, Jan Bartel wrote: >>>> Hi Weld developers, >>>> >>>> The Jetty project is looking at how we can do a tighter integration >>>> with Weld, also with a view to discussions in the Servlet Spec 4 >>>> committee to alleviate the necessity for CDI implementations to >>>> maintain jetty-specific initialisation code. >>>> >>>> During investigations, I noticed that we seem to have a conflict in >>>> the handling of a few annotations for classes that are managed by the >>>> servlet container (ie servlets, filters, listeners etc): >>>> >>>> @Resource >>>> @PostConstruct >>>> @PreDestroy >>>> >>>> As Jetty puts a servlet/filter/listener into service, we introspect >>>> the class and find the above annotations and process them. It seems >>>> that Weld does too, as I see the following failure for this code >>>> snippet: >>>> >>>> public class TestListener implements ServletContextListener >>>> { >>>> @Resource(mappedName="maxAmount") >>>> private Double maxAmount; >>>> } >>>> >>>> >>>> javax.naming.NameNotFoundException; remaining name 'maxAmount' >>>> at >>>> >>>> org.eclipse.jetty.jndi.local.localContextRoot.lookup(localContextRoot.java:429) >>>> at >>>> >>>> org.eclipse.jetty.jndi.local.localContextRoot.lookup(localContextRoot.java:533) >>>> at javax.naming.InitialContext.lookup(InitialContext.java:411) >>>> at >>>> >>>> org.jboss.weld.injection.spi.helpers.AbstractResourceServices.resolveResource(AbstractResourceServices.java:48) >>>> at >>>> >>>> org.jboss.weld.injection.spi.helpers.AbstractResourceServices$1.createResource(AbstractResourceServices.java:121) >>>> at >>>> >>>> org.jboss.weld.injection.AbstractResourceInjection.getResourceReference(AbstractResourceInjection.java:44) >>>> at >>>> >>>> org.jboss.weld.injection.AbstractResourceInjection.injectResourceReference(AbstractResourceInjection.java:53) >>>> at org.jboss.weld.util.Beans.injectEEFields(Beans.java:344) >>>> at >>>> >>>> org.jboss.weld.injection.producer.ResourceInjector$1.proceed(ResourceInjector.java:69) >>>> at >>>> >>>> org.jboss.weld.injection.InjectionContextImpl.run(InjectionContextImpl.java:48) >>>> at >>>> >>>> org.jboss.weld.injection.producer.ResourceInjector.inject(ResourceInjector.java:72) >>>> at >>>> >>>> org.jboss.weld.injection.producer.BasicInjectionTarget.inject(BasicInjectionTarget.java:121) >>>> at >>>> >>>> org.jboss.weld.environment.servlet.inject.AbstractInjector.inject(AbstractInjector.java:55) >>>> at >>>> >>>> org.jboss.weld.environment.jetty.JettyWeldInjector.inject(JettyWeldInjector.java:15) >>>> at >>>> >>>> org.jboss.weld.environment.jetty.WeldDecorator.decorate(WeldDecorator.java:105) >>>> at >>>> >>>> org.eclipse.jetty.util.DecoratedObjectFactory.decorate(DecoratedObjectFactory.java:77) >>>> at >>>> >>>> org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:335) >>>> at >>>> >>>> org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1349) >>>> at >>>> >>>> org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1342) >>>> at >>>> >>>> org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:743) >>>> at >>>> >>>> org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:257) >>>> at >>>> org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:505) >>>> >>>> >>>> Googling around, it is not clear to me exactly which of the Common >>>> Annotations (JSR250) that Weld supports and I'd appreciate some input >>>> from the Weld devs in order for Jetty to work out how best to move >>>> forward with Weld integration. >>>> >>>> In particular, I'd appreciate some clear feedback on which of the >>>> following @Resource annotation usages will be handled by Weld: >>>> >>>> @Resource on a class >>>> @Resource on a field >>>> @Resource on a method >>>> @Resource annotations without an accompanying @Producer annotation >>> @Resource on a field (with or without @Producer), @Resource on a method, >>> @PostConstruct and @PreDestroy are handled by Weld on a managed instance >>> (generally). >>>> >>>> Secondly, as can be seen from the stacktrace above, Weld is failing to >>>> find the matching JNDI entry for an @Resource annotation. This is >>>> because Weld appears not to be looking in "java:comp/env" namespace, >>>> although IIRC that is mandated by the JavaEE spec for EE managed >>>> classes (servlets/filters/listeners etc). So if Jetty delegates >>>> handling of some/all processing of @Resource, how do we ensure that >>>> Weld will be able to find the right JNDI entry? >>> This might be a bug in weld-servlet's ResourceInjectionServices >>> implementation. Can you file an issue at >>> https://issues.jboss.org/browse/WELD ? >>> >>>> thanks for your time, >>>> Jan >>> >>