[infinispan-dev] [Pull Request] Modular Classloading Compatibility

[Galder Zamarreño]

On May 3, 2011, at 2:33 PM, Sanne Grinovero wrote:

> 2011/5/3 "이희승 (Trustin Lee)" <trustin at gmail.com>:
>> On 05/03/2011 05:08 AM, Sanne Grinovero wrote:
>>> 2011/5/2 Manik Surtani <manik at jboss.org>:
>>>> 
>>>> On 1 May 2011, at 13:38, Pete Muir wrote:
>>>> 
>>>>>>> As in, user API?  That's a little intrusive... e.g., put(K, V, cl) ?
>>>>>> 
>>>>>> Not for put, since you have the class, just get, and I was thinking
>>>>>> something more like:
>>>>>> 
>>>>>> Foo foo = getUsing(key, Foo.class)
>>>>> 
>>>>> This would be a pretty useful addition to the API anyway to avoid user casts.
>>>> 
>>>> Maybe as an "advanced" API, so as not to pollute the basic API?  A bit like:
>>>> 
>>>> Foo f = cache.getAdvancedCache().asClass(Foo.class).get(key);
>>> 
>>> doesn't look much better than a cast, but is more cryptical :)
>>> 
>>> getting back to the classloader issue, what about:
>>> 
>>> Cache c = cacheManager.getCache( cacheName, classLoader );
>>> 
>>> or
>>> Cache c = cacheManager.getCache( cacheName ).usingClassLoader(classLoader );
>>> 
>>> BTW if that's an issue on the API, maybe you should propose it to
>>> JSR-107 as well ?
>> 
>> We have a configurable Marshaller, right?  Then why don't we just use
>> the class loader that the current Marshaller uses?
> 
> +1
> I like the clean approach, not sure how you configure the "current
> Marshaller" to use the correct CL ?
> Likely hard to do via configuration file :)

Well, the marshaller is a global component and so it's a cache manager level. You can't make any assumptions about it's classloader, particularly when lazy deserialization is configured and you want to make sure that the data of the cache is deserialized with the correct classloader when the user reads the data from the cache. This is gonna become even more important when we for example move to having a single cache for all 2LC entities or all EJB3 SFSBs where we'll definitely need multiple classloaders to access a single cache. 

--
Galder Zamarreño
Sr. Software Engineer
Infinispan, JBoss Cache