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I want to use Spring AOP in my spring application. While creating AOP proxy for net.sf.ehcache.CacheManager, spring context initialization fails with the below exception:

nested exception is org.springframework.aop.framework.AopConfigException: Could not
generate CGLIB subclass of class [class net.sf.ehcache.CacheManager]: Common causes of 
this problem include using a final class or a non-visible class; nested exception is 
net.sf.cglib.core.CodeGenerationException: net.sf.ehcache.CacheException-->Another   
unnamed CacheManager already exists in the same VM. Please provide unique names for 
each CacheManager in the config or do one of following:
1. Use one of the CacheManager.create() static factory methods to reuse same  
CacheManager with same name or create one if necessary
2. Shutdown the earlier cacheManager before creating new one with same name.
The source of the existing CacheManager is: InputStreamConfigurationSource 
[stream=java.io.ByteArrayInputStream@955b34]

Here's my understanding about this problem - Spring is trying to create AOP proxy for net.sf.ehcache.CacheManager, and it succeeds the first time and gives a default name to the CacheManager __DEFAULT__ (found this by adding debug statements to ehcache code, building it by source and using that in my application). Now if I've multiple cache managers like 'abcCacheManager' and 'xyzCacheManager' (of type EhCacheManagerFactoryBean), Spring encounters multiple net.sf.ehcache.CacheManagers and tries to create proxy objects (something like net.sf.ehcache.CacheManager$$EnhancerByCGLIB$$b18c5958) for all of them, but with EhCache >=2.5 version, we can't have more than one caches with same name under the same VM.

I'm using EhCache 2.5.1 and would like to avoid going back to 2.4 just for this purpose. I'm not sure if this is really the problem how I can overcome this problem.

Note: Note sure if this will help, but I also noticed from the debug statements that CacheManager no-arg constructor is invoked only by the spring/CGLIB proxy generator and xyzCacheManager invokes it by passing configuration as argument.

Swapnil
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1 Answers1

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Note : I'm answering this myself as it may help others who face the same problem.

jeha's comment on my question makes sense as I shouldn't have needed that proxy at the first place, but since I'm new to Spring AOP and proxies, I didn't know how auto-proxy mechanism works. As I modified the pointcut expressions in my advice, I didn't face the above problem after that. Prior to this, almost all the beans in the container were getting proxied and hence the problem.

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Swapnil
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