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Re: [Springframework-developer] Proxying Classes without a Default Constructor
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From: Colin S. <col...@ex...> - 2005-02-03 21:49:03
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I like the idea of at least exposing the constructor args on teh Cglib2AopProxy. If somebody really needs this functionality, then they really need it, and can get at it that way at least. Rob Harrop wrote: > Juozas assures me that 2.1 will be final next week so there should be > no problems on that front. Cglib2AopProxy won't run on 1.1.5 without > CGLIB 2.1 since I had to modify the code to take advantage of new > features. I can switch the class back if you'd prefer, or I can > probably put some detection logic in there to test for 2.1 or 2.0.2. > That way the code should run on 2.0.2, but one test won't pass - the > one that is fixed by the new feature. > > Rob > > Juergen Hoeller wrote: > >> OK, then I vote for closing it as "won't fix" :-) >> >> Regarding CGLIB 2.1: Suppressing constructor calls to bean property >> setters >> is fine, I guess, as this is a pretty common case even for JavaBeans >> with >> default constructors. CGLIB 2.1 should become final within the next 3 >> weeks, >> though; we definitely shouldn't delay Spring 1.1.5 because of it. >> >> Does Cglib2AopProxy still run on CGLIB 2.0.2, or do we have some central >> dependency on CGLIB 2.1? Would Spring 1.1.5 built against CGLIB 2.1 >> still >> run with CGLIB 2.0.2 on the class path? Else, we would force 1.1.5 >> users to >> upgrade their CGLIB version too, which we should avoid... >> >> BTW, I don't mind exposing the constructor-arg functionality on the >> internal >> Cglib2AopProxy itself, as we already do. I'd just prefer to not >> expose it on >> the user-visible ProxyFactory/ProxyFactoryBean. >> >> Juergen >> >> >> -----Original Message----- >> From: spr...@li... >> [mailto:spr...@li...]On Behalf >> Of Rob Harrop >> Sent: Thursday, February 03, 2005 10:05 PM >> To: spr...@li... >> Subject: Re: [Springframework-developer] Proxying Classes without a >> Default Constructor >> >> >> Actually, I agree with this, I just want to get this issue fixed or >> closed - I feel guilty every time I look at JIRA :). The upgrade to >> 2.1dev was to fix the problem related to side effects of calling >> constructors that initialized state for a 2nd time during proxy >> creation. The creation of a proxy with CGLIB will no longer reset any >> bean state if the constructor has calls to initialize the state. >> >> Juergen Hoeller wrote: >> >> >> >>> Rob, everybody, >>> >>> Some thoughts on the level of our CGLIB support. I have hinted at this >>> before; I guess it is the time to seriously discuss desirable and >>> undesirable features now. >>> >>> I'm inclined to argue that we shouldn't support proxying of classes >>> without >>> default constructor in the first place. It feels so wrong to have to >>> >> >> specify >> >> >>> constructor args on a ProxyFactoryBean... and to actually execute >>> the full >>> constructor of the target class just for the proxy instance, with those >>> problems of suppressing method calls in the constructor (to avoid side >>> effects) etc. >>> >>> For my taste, this goes too far. CGLIB proxies are already debatable >>> with >>> default constructors that perform initialization work, and simply >>> feel like >>> a big hack when used with a non-default constructor. IMO, the >>> proxy-based >>> AOP approach is not recommendable for such needs: Go for full-blown >>> AspectJ >>> or add the additional behavior in a more traditional way (wrapping, >>> subclassing, whatever). >>> >>> I'd like to hear opinions on the value of proxying classes with >>> non-default >>> constructors. I currently prefer to avoid that feature in the first >>> place, >>> but I'm open to getting convinced otherwise. >>> >>> Juergen >>> >>> >>> P.S.: I suppose that the CGLIB upgrade to 2.1-dev was necessary for >>> this? >>> Does this mean that we could stick with CGLIB 2.0.2 (for Spring >>> 1.1.5) if >>> >> >> we >> >> >>> avoid supporting non-default constructors for proxies? >>> >>> >>> -----Original Message----- >>> From: spr...@li... >>> [mailto:spr...@li...]On Behalf >>> Of Rob Harrop >>> Sent: Thursday, February 03, 2005 9:31 PM >>> To: spr...@li... >>> Subject: [Springframework-developer] Proxying Classes without a Default >>> Constructor >>> >>> >>> All, >>> >>> I'm going to raise this issue again in the hope that we can reach a >>> consensus before 1.1.5. I have modified Cglib2AopProxy to support >>> classes without a default constructor, we just need to make this >>> functionality available in a configurable manner. Ideally this would be >>> done with setConstructorArgs(Object[]) and >>> setConstructorArgTypes(Class[]) methods on ProxyFactoryBean. >>> >>> Rob >>> |
