On Fri, Jun 28, 2013 at 11:15 AM, Martin Grigorov <mgrigo...@apache.org>wrote:
> Hi, > > > On Fri, Jun 28, 2013 at 12:43 AM, Bas Gooren <b...@iswd.nl> wrote: > >> Hi Andreas, >> >> My guess is that the GuiceComponentInjector proxies are "detached" when >> the page is serialized. >> The last page (or the last N pages) are kept in memory by wicket (I >> think, last I checked was some years ago). >> >> Checking ... >> Yes, see LazyInitProxyFactory and its nested class JdkJHandler (which is >> used for injected interfaces). >> The proxy is replaced on serialization. >> >> Somehow I always thought the proxies were also detached when the page is >> detach()-ed. Guess not :-) >> > > This explains it! > The last used page instance is stored in the HttpSession, and this keeps a > reference to a proxy with a closed EntityManager. > > Wicket detaches all components and their default models, but there is no > logic to null-ify the transient field in JdkHandler - > https://github.com/apache/wicket/blob/master/wicket-ioc/src/main/java/org/apache/wicket/proxy/LazyInitProxyFactory.java?source=c#L375 > > The simplest solution is to not keep the 'target' as a field at all. Just > as the IProxyTargetLocator for the service at every usage. Will this be > slow ?! > This should read: Just ask ... > > >> >> Met vriendelijke groet, >> Kind regards, >> >> Bas Gooren >> >> Op 27-6-2013 23:37, schreef Andreas Lundblad: >> >> On Thu, Jun 27, 2013 at 11:25 PM, Bas Gooren <b...@iswd.nl> wrote: >>> >>>> Hi Andreas, >>>> >>>> When your validator fails, you remain on the FormPage. A quick debug >>>> session >>>> shows me that the injected IService remains the same accross requests. >>>> >>> I've seen this too. I thought that this didn't matter since, as you >>> said: "The GuiceComponentInjector which is set-up in the wicket >>> application injects proxies". >>> >>> The fix for your problem is simple, and a best practice anyway: inject >>>> Provider<EntityManager> in your service. >>>> >>>> It's a best practice since the service does not know the "scope" of the >>>> entitymanager, all it knows is that the entitymanager has a different >>>> lifecycle; Your service may be instantiated and kept around for the time >>>> your app is running, but could also be instantiated on the fly when >>>> needed. >>>> That's one of the reasons why Provider<> was invented: if the scope is >>>> different, a provider allows you to nicely deal with it. >>>> >>>> In case you are not familiar with providers: it has no negative >>>> side-effects >>>> in terms of performance. >>>> The guice-persist module binds the EntityManager per request, so all >>>> calls >>>> to Provider<EntityManager> while in the same request will yield the >>>> exact >>>> same EntityManager instance. >>>> >>>> >>>> >>>> PS See https://code.google.com/p/**google-guice/wiki/** >>>> InjectingProviders<https://code.google.com/p/google-guice/wiki/InjectingProviders>(header >>>> "Providers for Mixing Scopes"). >>>> >>> Thank you Bas for this excellent answer. Much appreciated. >>> >>> -- Andreas Lundblad >>> >>> ------------------------------**------------------------------** >>> --------- >>> To unsubscribe, e-mail: >>> users-unsubscribe@wicket.**apache.org<users-unsubscr...@wicket.apache.org> >>> For additional commands, e-mail: users-h...@wicket.apache.org >>> >>> >> >
