Re: [rules-users] Hibernate proxy objects equality tests failing in Drools 5

From: Guto <guto(a)guto.net&gt; Subject: Re: [rules-users] Hibernate proxy objects equality tests failing in Drools 5 To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; Date: Wednesday, May 6, 2009, 7:43 AM I don´t have a clue why is not working eather. Unfortunelly I can´t really rely on a.id == b.id ´cause I have rules like: $participante:Participante() && $participacoes: ArrayList(size == 0) from collect(ParticipacaoCiclo(participante == $participante && saidaPosto == null && periodo == 1 )) Do eager fetching, will really reduce my perfomace, since most of my collection properties have a huge amount of data (I don´t use that data inside the drools session, I don´t need them). I have 2 clients one is an UnitTest that access the EJB and the other is an JSF 1.2 webclient (the real application itself). I´m not using groovy (not in this project, however I found that really interesting). thanks. just a question (==) will be translated to (equals) right? > With the new hibernate jars and the migration to the new Javassist, > what hibernate is essentially doing is dynamically generating > hibernate proxy objects that should subclass the original file. > Here's the interesting part. > > In groovy, comparing two hibernate objects: > > a.a == b.a > > works fine when they are the same type of object. Under groovy, "==" > uses "equals()" to do the comparison. That appears to work all good. > However, taking these same two objects into Drools and comparing their > subproperty when they are lazily loaded will cause the problems that > a.a no longer equals to b.a. Yet under groovy, it still says they are > equal. > > There could be one of 2-3 things that can be done to fix this, which I > haven't entirely tried. > > 1) implement your own version of equals() and hashCode() and use the > instanceOf() hibernate util method to do comparison. Sadly, I have > over 50 domains objects and I'm hoping not to have to implement all > the methods. > > 2) do a eager fetch of the properties. This is probably the best and > easy way, but I am getting this working well under Grails/groovy. > Somehow it's still fetching them as proxy objects, but just loaded. > Either that or the eager fetching isn't even working (I've yet to > fully test this yet with hibernate logging turned on to check). > > 3) use each domain's identity or some unique constraint to do the > equality check. This is my current "cheating" way of getting around > the problem. I simply use a.a.id == b.a.id. However, this poses an > additional complexity where I actually have to do null checks for the > property. Otherwise, I'd get NPEs all over the place. > > At the end of the day, I don't see why Drools cannot see proxy objects > as equal. The only way I can think of is that there is some sort of > direct object/class type check in Drools that's causing it not to > realize that two objects are equal. But I could be wrong, and I hope > I'm wrong. :) > > -Chris > > On May 4, 2009, at 1:29 PM, Guto wrote: > >> Thanks Greg, >> >> But it´s not a lazy loading problem at all. I am not using any kind of >> lazy attribute inside the statefull drools session... >> >> Unfortunelly, i´ve just upgrade from drools 4GA to 5CR1 and the >> problem >> persist. Now I will try to make CLONES of the objects the came from >> the >> bank, just to see if that (temporary) solution works. >> >>> >>> Do you need the lazy loading functionality that proxies provide? >>> It seems >>> to me that if you have an EJB call that's providing the objects >>> loaded >>> from hibernate, that's probably not the case. (i.e. once the >>> objects are >>> loaded and returned by the EJB method, the hibernate session may no >>> longer >>> be available, so lazy loading could fail anyway.) If you have >>> access to >>> the hibernate mapping just set lazy="false" on your class mappings. >>> >>> Not to say that this use case shouldn't be addressed with drools, >>> but if >>> you're under a deadline... :) >>> >>> --- On Mon, 5/4/09, Guto <guto(a)guto.net&gt; wrote: >>> >>>> From: Guto <guto(a)guto.net&gt; >>>> Subject: Re: [rules-users] Hibernate proxy objects equality tests >>>> failing in Drools 5 >>>> To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; >>>> Date: Monday, May 4, 2009, 2:42 PM >>>> Just now I notice one thing. The application that i am >>>> building is >>>> compleatly EJB centric. I have um EJB project that usually >>>> do all the >>>> database stuff, and another EJB project for the drools >>>> rules. Lets call >>>> them >>>> EJB-DATA and EJB-DROOLS. When the client calls for an >>>> specific data that >>>> must be threated thru the Drools rules it calls an >>>> Stateless method from >>>> EJB-DATA, inside the method, it gather the necessarie >>>> parameter >>>> information and them inside the EJB-DATA method it calls >>>> the EJB-DROOLS. >>>> (hoping not been confusing) >>>> >>>> (if you are using an fixed space font, here comes the >>>> sequence) >>>> >>>> Client --> EJB-DATA (gather information inside) --> >>>> EJB-DROOLS >>>> <-- return to Client data from EJB-DROOLS<-- >>>> return to EJB-DATA >>>> >>>> Now looking over my two projects, I notice that I make them >>>> apart so one >>>> could evolve with interfering the other. >>>> >>>> When I call EJB-DROOLS directly from an UNIT-TEST client >>>> with pojos >>>> parameters intantiated by the test, it pass. >>>> >>>> When I call EJB-DATA from an UNIT-TEST client (pojos >>>> created inside this), >>>> first i was getting an CORBA exception ´cause of a >>>> ClassNotFoundException >>>> for the hibernate PersistenceBag. >>>> >>>> That´s the way i figure out that my objects are bagged or >>>> proxied thru >>>> hibernate. >>>> >>>> I´ve tried to use the EntityManager.clear() (EJB3-JPA) to >>>> clean the pojos >>>> before send it and make them more like the ones from the >>>> first unit-test, >>>> but even so it´s not working. >>>> >>>> Then, possible solutions: >>>> 1) Make equality test works from objects that came from >>>> hibernate from jpa. >>>> 2) Kill the proxies and make them simple objects (not >>>> hibernate derivated). >>>> 3) don´t know, but i´m been realy in a deadline here. >>>> >>>> >>>> again >>>> thanks for anyone in advance ! >>>> >>>> -- >>>> Guto Maia >>>> Consultor de TI / Desenvolvedor >>>> CSM - SCJP- SCWCD - SCBCD - ZCE >>>> >>>> >>>> >>>> >>>> >>>>> In fact, i´m really using JPA with hibernate as an >>>> provider. >>>>> >>>>> Could you send me your hibernate config? I will >>>> compare some proprieties >>>>> of tyour hibernate.config with my persistence.xml. >>>>> >>>>> I plenty sure that the rule is ok, since it is working >>>> with the unit test. >>>>> >>>>> If you need any help to mimic what your using with >>>> JPA, just ask. >>>>> >>>>> Thanks anyway. >>>>> >>>>> >>>>>> >>>>>> I'm using non-proxied hibernate backed POJOs >>>> in drools with no problems. >>>>>> (THe pojos aer generaed by hbm2java.) I'll >>>> try configuring for proxies >>>>>> to >>>>>> see what happens. >>>>>> >>>>>> >>>>>> --- On Mon, 5/4/09, Gustavo Maia Neto >>>> <guto(a)guto.net&gt; wrote: >>>>>> >>>>>>> From: Gustavo Maia Neto <guto(a)guto.net&gt; >>>>>>> Subject: Re: [rules-users] Hibernate proxy >>>> objects equality tests >>>>>>> failing in Drools 5 >>>>>>> To: "Rules Users List" >>>> <rules-users(a)lists.jboss.org&gt; >>>>>>> Date: Monday, May 4, 2009, 11:28 AM >>>>>>> on this afternoon I will migrate to Drools 5 >>>> CR1, >>>>>>> unfortunelly i'm not >>>>>>> sure if it will solve my problem. >>>>>>> >>>>>>> Does anyone else uses Drools with objects that >>>> came from an >>>>>>> hibernate, >>>>>>> (proxies)? >>>>>>> >>>>>>> Also, i'm not using any proxy to fetch >>>> lazy data inside >>>>>>> my Drools >>>>>>> stateful session. >>>>>>> >>>>>>> thanks >>>>>>> >>>>>>> Guto escreveu: >>>>>>>> I was following that subject on markmail, >>>> and them >>>>>>> I've enterred the >>>>>>>> user-group (so subject and body are >>>> coppied from >>>>>>> them). I've got the >>>>>>>> exactly same problem. When I use the >>>> rules with >>>>>>> objects the came from the >>>>>>>> database (thru JPA hibernate provider), >>>> thouse rules >>>>>>> never match. When I >>>>>>>> do the same from Pojos hand made for unit >>>> test, it >>>>>>> work. >>>>>>>> >>>>>>>> I don't know what really happen, but >>>> i'm sure >>>>>>> that it is an equality test >>>>>>>> falling 'cause of the hibernate >>>> proxys. >>>>>>>> >>>>>>>> I don't get also any kind of error or >>>> exception, >>>>>>> since it ALL WORK. Just >>>>>>>> the rule isn't be acomplished. >>>>>>>> >>>>>>>> I'm using EJB3 + JPA (hibernate >>>> provider) and >>>>>>> Drools 4 GA; >>>>>>>> >>>>>>>> thanks in advance for any help >>>>>>>> >>>>>>> >>>>>>> >>>> _______________________________________________ >>>>>>> rules-users mailing list >>>>>>> rules-users(a)lists.jboss.org >>>>>>> >>>> https://lists.jboss.org/mailman/listinfo/rules-users >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> rules-users mailing list >>>>>> rules-users(a)lists.jboss.org >>>>>> >>>> https://lists.jboss.org/mailman/listinfo/rules-users >>>>>> >>>>> >>>>> >>>>> -- >>>>> Guto Maia >>>>> Consultor de TI / Desenvolvedor >>>>> CSM - SCJP- SCWCD - SCBCD - ZCE >>>>> >>>>> _______________________________________________ >>>>> rules-users mailing list >>>>> rules-users(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/rules-users >>>>> >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> rules-users mailing list >>>> rules-users(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >>> >>> >>> _______________________________________________ >>> rules-users mailing list >>> rules-users(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/rules-users >>> >> >> >> -- >> Guto Maia >> Consultor de TI / Desenvolvedor >> CSM - SCJP- SCWCD - SCBCD - ZCE >> >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > . > -- Guto Maia Consultor de TI / Desenvolvedor CSM - SCJP- SCWCD - SCBCD - ZCE _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users