Re: [jonas-team] Re: [enhydra] Moving XMLC from BCEL to ASM

[David Li <taweili@xxxxxxxxx>]

Hi  Slobodan,

  I think the problem should be less a concern with JOnAS if the  
classloading of the servlet container are done per Servlet Spec.

Version 2.4, SRV 9.5 states:

The Web application classloader must load classes from the  
WEB-INF/classes directory first, and then from library JARs in the  
WEB-INF/lib directory.

From 9.7.1 talking about container library loading:

The files placed within this directory must be available across all Web  
applications. The location of this directory is container-specific.The  
classloader the servlet container uses for loading these library files  
must be the same for all Web applications within the same JVM. This  
classloader instance must be some where in the chain of parent class  
loaders of the Web application class loader.

If I read this correctly, if a ASM jar exists in WEB-INF/lib, it should  
have precedence over the one used by the container. Sounds like there  
shouldn't be problem using different version of ASM in XMLC (goes to  
WEB-INF) and container's library.

However, XMLC is exposed in Enhydra as system wide service, this may be  
a problem.

On Jan 27, 2005, at 6:36 PM, Gérard Vandome wrote:

>  Hello Slobodan,
>
>  I am not sure of the answer, so through this reply I post it also on  
> jonas-team (thanks to jonas-team members to give more infos on the use  
> of BCEL if needed, and  when they have some time to investigate the  
> way to move to ASM if this is feasible).
>
>  Please don't hesitate to send any message with any question related  
> to jonas on the jonas-team mailing list (please subscribe to the  
> jonas-team mailing list if not already done in order to avoid to be  
> moderated).I think this will help us to work more together.
>
>
>  Slobodan Vujasinovic wrote:
> Hi,
>
> We, in Enhydra and Enhydra Enterprise, are not using BCEL explicitly,  
> but
> some of our components (integrated tools) are (like XMLC)!
>
> JOnAS: Some Ant tasks in JOnAS use BCEL (building of JOnAS examples,
> recompilation of the Axis package from the source and I think that  
> they have
> dependency in their 'GenericDeploymenTool')!
>
>
>
> Barracuda: BCEL is actually used, as I know, just through XMLC  
> (deferred
> parsing)!
>
> Ant: Library dependencies (bcel.jar) - classfileset data type,
> JavaClassHelper used by the ClassConstants filter reader and  
> optionally used
> by ejbjar for dependency determination.
>
> MX4J: BCELMBeanInvoker -  It uses the BCEL to generate the required  
> bytecode
> on-the-fly.  MBeanInvoker that generates on-the-fly implementations to  
> call
> standard MBeans directly, instead of using reflection.
>
>
> Therefore, the conclusion would be that we have no reason to oppose  
> your
> decision to move (from BCEL) to ASM.
> To keep this Enhydra Components (JOnAS, Ant and MX4J) fully functional  
> we
> will leave current BCEL version present in Enhydra.
> And, since we are not using ASM in Enhydra (jet) you don't need to  
> have any
> concerns regarding version conflicts!
>
> Regards,
>     Slobodan Vujasinovic
> Enhydra Development Team
>
>
> ----- Original Message -----
> From: "David Li" <taweili@xxxxxxxxx>
> To: <xmlc@xxxxxxxxxxxxx>
> Cc: <enhydra@xxxxxxxxxxx>
> Sent: Wednesday, January 26, 2005 9:30 PM
> Subject: [enhydra] Moving XMLC from BCEL to ASM
>
>
>
> Hi,
>
>    I am planning on moving XMLC from BECL to ASM. I'd like to know if
> anyone has concern about this, especially the guys from Enhydra team.
> Are you using ASM for anything in Enhydra? I am trying to avoid a
> version and dependency conflict.
>
> David
>
>
>
>
>
> ----------------------------------------------------------------------- 
> -----
> ----
>
>
>
> --
> You receive this message as a subscriber of the enhydra@xxxxxxxxxxxxx
>
> mailing list.
>
> To unsubscribe: mailto:enhydra-unsubscribe@xxxxxxxxxxxxx
> For general help: mailto:sympa@xxxxxxxxxxxxx?subject=help
> ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
>
>
>
>
>
>
> --
> You receive this message as a subscriber of the enhydra@xxxxxxxxxxxxx   
> mailing list.
> To unsubscribe: mailto:enhydra-unsubscribe@xxxxxxxxxxxxx
> For general help: mailto:sympa@xxxxxxxxxxxxx?subject=help
> ObjectWeb mailing lists service home page: http://www.objectweb.org/wws
>
>
>
>
> --
> Gérard Vandôme                          JOnAS Project Manager
>  Gerard.Vandome@xxxxxxxxxxxxx             http://jonas.objectweb.org
> Take action against software patents    http://swpat.ffii.org
>
>
>
>
> --
> You receive this message as a subscriber of the  
> jonas-team@xxxxxxxxxxxxx mailing list.
> To unsubscribe: mailto:jonas-team-unsubscribe@xxxxxxxxxxxxx
> For general help: mailto:sympa@xxxxxxxxxxxxx?subject=help
> ObjectWeb mailing lists service home page: http://www.objectweb.org/wws