Re: [cdi-dev] Feedback - CDI bootstrap API (CDI-26)

This is actually based on what we discussed in one of the EG meetings http://transcripts.jboss.org/meeting/irc.freenode.org/cdi-dev/2015/cdi-de... John On Wed, Mar 4, 2015 at 4:05 AM Jozef Hartinger <jharting(a)redhat.com <mailto:jharting@redhat.com>> wrote: Well it's nowhere given that we must have two separate interfaces for this. We can combine the start/stop API with the existing one to provide an application with a single reference representing the CDI container. On 02/28/2015 07:05 PM, John D. Ament wrote: > Maybe I'm misreading, but I don't see us adding another API to do > the same thing here - we're introducing new functionality. > > CDIContainer/Loader on startup/shutdown of the application > > CDI for runtime usage within the application to interact with the > container. > > John > > On Fri, Feb 27, 2015 at 3:40 AM Romain Manni-Bucau > <rmannibucau(a)gmail.com <mailto:rmannibucau@gmail.com>> wrote: > > sure I fully agree excepted I think introducing yet another > API to do > the same thing is not good so super tempting to skip it and > wait for > feedbacks rather than introducing it eagerly. > > > Romain Manni-Bucau > @rmannibucau > http://www.tomitribe.com > http://rmannibucau.wordpress.com > https://github.com/rmannibucau > > > 2015-02-27 8:05 GMT+01:00 Jozef Hartinger > <jharting(a)redhat.com <mailto:jharting@redhat.com>>: > > My point is that from the application perspective, the user > obtains one > > container handle for eventual shutdown (CDIContainer) and > then looks up a > > different container handle (CDI) that they can use for real > work (lookup / > > event dispatch / etc.) It would be cleaner if the container > gave away a > > single handle that can do all of that. > > > > > > On 02/26/2015 05:42 PM, Romain Manni-Bucau wrote: > > > > Not sure I get how a CDI instance can help. > > > > But container.getBeanManager() sounds nice is not a > shortcut for > > CDI.current().getBm() otherwise it looks like duplication > to me. > > > > Can we make container not contextual - dont think so? If so > it makes sense > > otherwise I fear it doesnt add much. > > > > Le 26 févr. 2015 16:19, "Jozef Hartinger" > <jharting(a)redhat.com <mailto:jharting@redhat.com>> a écrit : > >> > >> I like the initialize + close() combination and the > try-with-resources > >> usage. > >> What looks weird to me is that at line one you obtain a > container handle: > >> > >> try (CDIContainer container = CDIContainer.newCDIContai... > >> CDI.current().getBeanManager() ... > >> > >> and then at line two you call a static method to perform a > container > >> lookup :-/ > >> > >> An API that allows you to use the container handle you > already got is way > >> better IMO, e.g.: > >> > >> try (CDIContainer container = CDIContainer.newCDIContai... > >> container.getBeanManager() > >> > >> If CDIContainer.newCDIContainer() returns an CDI instance > or its subclass, > >> we get this easily. > >> > >> On 02/26/2015 08:58 AM, Romain Manni-Bucau wrote: > >>> > >>> Hi guys > >>> > >>> why note keeping it simple? > >>> > >>> try (CDIContainer container = > CDIContainer.newCDIContainer(/* optional > >>> map to configure vendor features */)) { > >>> CDI.current().getBeanManager().... > >>> } > >>> > >>> Not sure the point having initialize() + having shutdown > = close > >>> really makes the API more fluent and modern IMO. > >>> > >>> Also to be fully SE I guess provider() method would be > needed even if > >>> optional (SPI usage by default): > >>> > >>> try (CDIContainer container = > >>> > >>> > CDIContainer.provider("org.jboss.weld.WeldCdiContainerProvider").newCDIContainer()) > >>> { > >>> CDI.current().getBeanManager().... > >>> } > >>> > >>> Finally I think having a kind of getInstance shortcut > could be a plus for > >>> SE: > >>> > >>> try (CDIContainer container = > CDIContainer.newCDIContainer()) { > >>> container.newInstance(MyAppRunner.class /* optional > qualifiers */ > >>> ).run(args); > >>> } > >>> > >>> Using container to get an instance would create the > instance and bind > >>> it to the container lifecycle (mainly for predestroy) > avoiding this > >>> boilerplate code in all main which will surely only be > used to launch > >>> a soft. > >>> > >>> wdyt? > >>> > >>> > >>> > >>> Romain Manni-Bucau > >>> @rmannibucau > >>> http://www.tomitribe.com > >>> http://rmannibucau.wordpress.com > >>> https://github.com/rmannibucau > >>> > >>> > >>> 2015-02-26 8:32 GMT+01:00 Jozef Hartinger > <jharting(a)redhat.com <mailto:jharting@redhat.com>>: > >>>> > >>>> Comments inline > >>>> > >>>> On 02/25/2015 05:53 PM, John D. Ament wrote: > >>>> > >>>> Sorry Jozef, your email fell into the pits of google > inbox's "smart > >>>> sorting" > >>>> features. > >>>> > >>>> On Thu, Feb 12, 2015 at 3:18 AM Jozef Hartinger > <jharting(a)redhat.com <mailto:jharting@redhat.com>> > >>>> wrote: > >>>>> > >>>>> Hi John, comments inline: > >>>>> > >>>>> > >>>>> On 02/11/2015 06:02 PM, John D. Ament wrote: > >>>>> > >>>>> Jozef, > >>>>> > >>>>> Most of what you see there is taken from the original > doc, since > >>>>> everyone > >>>>> seemed to be in agreement. I think the map is just a > safeguard in case > >>>>> of > >>>>> additional boot options available in some > implementations (e.g. I think > >>>>> OWB/OpenEJB have some options.. currently OpenEJB > supports an embedded > >>>>> CDI > >>>>> boot mode). > >>>>> > >>>>> No, I am fine with the map. What I am questioning is > the type of the > >>>>> map. > >>>>> Usually, data structures with a similar purpose use > Strings as their > >>>>> keys. > >>>>> This applies to ServletContext attributes, > InvocationContext data, > >>>>> Servlet > >>>>> request/session attributes and others. I am therefore > wondering whether > >>>>> there is a usecase for the proposed unbound key > signature or not. > >>>> > >>>> > >>>> I think that's more of a placeholder, I was assuming it > would be > >>>> Map<String,Object> once we clarify everything. > >>>> > >>>>> > >>>>> > >>>>> We spoke a few times about BeanManager vs CDI. > BeanManager was > >>>>> preferable > >>>>> since there's no easy way to get the the instance, CDI > is easier to get > >>>>> and > >>>>> more aligned with how you would get it. Usually people > expect the > >>>>> BeanManager to be injected or available via JNDI, > neither would be the > >>>>> case > >>>>> here. > >>>>> > >>>>> If CDI 2.0 targets Java SE then this container > initialization API will > >>>>> become something that ordinary application developers > use to start/stop > >>>>> CDI > >>>>> in their applications. It therefore cannot be > considered an SPI but > >>>>> instead > >>>>> should be something easy to use. On the other hand, > BeanManager is > >>>>> definitely an SPI. It is used in extension, frameworks > and generally > >>>>> for > >>>>> integration. Not much by applications directly. > Therefore, I don't see > >>>>> how > >>>>> the container bootstrap API and BeanManager fit > together. IMO the > >>>>> bootstrap > >>>>> API should expose something that makes common tasks > (obtaining a > >>>>> contextual > >>>>> reference and firing and event) easy, which the CDI > class does. > >>>>> > >>>>> Plus do not forget that BeanManager can be obtained > easily using > >>>>> CDI.getBeanManager(). > >>>> > >>>> > >>>> I'm not disagreeing. There's a few things I'd consider: > >>>> > >>>> - Is this mostly for new apps or existing? If existing, > it's probably > >>>> using > >>>> some internal API, if new it can use whatever API we give. > >>>> - I don't want to return void, we should give some kind > of reference > >>>> into > >>>> the container when we're done booting. > >>>> > >>>> Agreed, we should not be returning void. > >>>> > >>>> - CDI is a one step retrievable reference, where as > BeanManager is a two > >>>> step reference. With that said, BeanManager makes more > sense to return > >>>> here. Another thought could be we invent some new class > that has both, > >>>> but > >>>> that's really redundant. > >>>> > >>>> Why do you think BeanManager makes more sense here? > Especially given the > >>>> assumption that application code is going to call this > init/shutdown > >>>> API, I > >>>> don't see BeanManager as making more sense. > >>>> > >>>> > >>>>> > >>>>> > >>>>> Yes, this is the container start API. Sounds like you > have some good > >>>>> ideas for things like XML configuration or programmatic > configuration, > >>>>> both > >>>>> of which are being tracked under separate tickets. One > idea might be > >>>>> for an > >>>>> optional param in the map to control packages to > scan/ignore, in that > >>>>> map. > >>>>> > >>>>> I am wondering whether this configuration should be > something optional > >>>>> built on top of the bootstrap API or whether we should > consider making > >>>>> it > >>>>> mandatory. Either way, we cannot add the bootstrap API > to the spec > >>>>> without > >>>>> explicitly defining how it behaves. My implicit > assumption of the > >>>>> proposal > >>>>> is that the container is supposed to scan the entire > classpath for > >>>>> explicit > >>>>> or implicit bean archives (including e.g. rt.jar), > discover beans, fire > >>>>> extensions, etc. This worries me as this default > behavior is far from > >>>>> being > >>>>> lightweight, which CDI for Java SE initially aimed to be. > >>>> > >>>> > >>>> Yes, the spec must be updated to reflect the behavior of > SE mode. I > >>>> plan to > >>>> get that completely into the google doc before opening > any spec changes > >>>> in a > >>>> PR. > >>>> > >>>>> > >>>>> > >>>>> We didn't want to over load the CDI interface. It > already does a lot. > >>>>> This is really SPI code, CDI even though it's in the > spi package is > >>>>> used in > >>>>> a lot of application code. > >>>>> > >>>>> I would personally prefer to have it all in one place. > Having > >>>>> CDIContainer, CDIContainerLoader, CDI and CDIProvider > makes it more > >>>>> difficult to know when to use what. > >>>> > >>>> > >>>> The problem is that most CDI (the interface) operations > are against a > >>>> running container. I think we spoke about leveraging > CDIProvider at one > >>>> point (in fact, I mistakenly called CDIContainer > CDIProvider not even > >>>> realizing it was there). I doubt that most app > developers use it > >>>> currently, > >>>> there's not even a way to get a reference to it that I'm > aware of. It's > >>>> used by the implementor only. > >>>> > >>>> I don't think there's a conflict. CDI class would still > only provide > >>>> methods > >>>> to be run against a running container. The difference is > that there > >>>> would be > >>>> additional static methods to get this running container > (CDI class) to > >>>> you > >>>> by starting the container. > >>>> > >>>> Either way, I agree that reusing CDIProvider is a must. > There is no > >>>> reason > >>>> to define a new class for the same purpose. > >>>> > >>>> > >>>> I expect that my changes in the CDI spec around this > will state, along > >>>> the > >>>> lines of: > >>>> > >>>> To retrieve a CDIContainer to launch, do this: > >>>> > >>>> CDIContainer container = > CDIContainerLocator.getCDIContainer(); > >>>> container.initialize(); > >>>> ... do work > >>>> > >>>> Once you want to shutdown the container, do this: > >>>> > >>>> container.shutdown(); > >>>> > >>>> (we may want to consider implementing AutoCloseable, an > oversight on my > >>>> part) > >>>> > >>>> and then later on > >>>> > >>>> - What happens if I call CDIContainerLocator in an app > server > >>>> > >>>> - It throws an IllegalStateException. > >>>> > >>>> - The container provides no beans of type CDIContainer, > it is managed > >>>> outside of the CDI container. > >>>> > >>>> > >>>>> > >>>>> > >>>>> John > >>>>> > >>>>> On Wed Feb 11 2015 at 4:21:50 AM Jozef Hartinger > <jharting(a)redhat.com <mailto:jharting@redhat.com>> > >>>>> wrote: > >>>>>> > >>>>>> Hi John, some thoughts: > >>>>>> > >>>>>> - instead of using BeanManager it makes more sense to > me to return a > >>>>>> CDI > >>>>>> instance, which is a more user-friendly API (and it > also exposes > >>>>>> access to > >>>>>> BeanManager) > >>>>>> - is there a usecase for arbitrary keys of the > "params" map or is > >>>>>> Map<String, ?> sufficient? > >>>>>> - if we could move the shutdown() method from > CDIContainer to the > >>>>>> actual > >>>>>> container handle that we obtain from initialize(), > that would look > >>>>>> more > >>>>>> object-oriented > >>>>>> - what exactly is initialize() supposed to do? Is it > supposed to start > >>>>>> scanning the entire classpath for CDI beans? That > could be a problem > >>>>>> especially with spring-boot-like fat jars. I think we > need an API to > >>>>>> tell > >>>>>> the container which classes / packages to consider. > Something like > >>>>>> Guice's > >>>>>> binding API perhaps? > >>>>>> > >>>>>> - the proposal makes me wonder whether retrofitting > this functionality > >>>>>> to > >>>>>> the CDI class wouldn't be a better option. It could > look like: > >>>>>> > >>>>>> CDI container = CDI.initialize(); > >>>>>> container.select(Foo.class).get(); > >>>>>> container.shutdown(); > >>>>>> > >>>>>> compare it to: > >>>>>> > >>>>>> CDIContainer container = CDIContainerLoader. > getCDIContainer(); > >>>>>> BeanManager manager = container.initialize(); > >>>>>> manager.getBeans(...); > >>>>>> container.shutdown(manager); > >>>>>> > >>>>>> > >>>>>> On 02/10/2015 06:58 PM, John D. Ament wrote: > >>>>>> > >>>>>> All, > >>>>>> > >>>>>> I have the updated API here, and wanted to solicit any > final feedback > >>>>>> before updating the google doc and spec pages. > >>>>>> > >>>>>> > >>>>>> > >>>>>> > https://github.com/johnament/cdi/commit/2c362161e18dd521f8e83c27151ddad46... > >>>>>> > >>>>>> Let me know your thoughts. > >>>>>> > >>>>>> Thanks, > >>>>>> > >>>>>> John > >>>>>> > >>>>>> > >>>>>> _______________________________________________ > >>>>>> cdi-dev mailing list > >>>>>> cdi-dev(a)lists.jboss.org <mailto:cdi-dev@lists.jboss.org> > >>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev > >>>>>> > >>>>>> Note that for all code provided on this list, the > provider licenses > >>>>>> the > >>>>>> code under the Apache License, Version 2 > >>>>>> (http://www.apache.org/licenses/LICENSE-2.0.html). For > all other ideas > >>>>>> provided on this list, the provider waives all patent > and other > >>>>>> intellectual > >>>>>> property rights inherent in such information. > >>>>>> > >>>>>> > >>>> > >>>> _______________________________________________ > >>>> cdi-dev mailing list > >>>> cdi-dev(a)lists.jboss.org <mailto:cdi-dev@lists.jboss.org> > >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev > >>>> > >>>> Note that for all code provided on this list, the > provider licenses the > >>>> code > >>>> under the Apache License, Version 2 > >>>> (http://www.apache.org/licenses/LICENSE-2.0.html). For > all other ideas > >>>> provided on this list, the provider waives all patent > and other > >>>> intellectual > >>>> property rights inherent in such information. > >> > >> > > >