Hi,
I have enabled second level cache for parent and its child collection. The section of hbm for the child objects is given below.

I use criteria query on parent , close the session and return the parent. Now when I try to get the child elements I get the exception below.

I searched the list, but could not get much clue.

Thanks
Ashwani




Hibernate version:3.0

Mapping documents:
<set name="codeAttributes" lazy="false" inverse="true" cascade="all,delete-orphan" order-by="ATTRIBUTE_NAME">
<cache usage="transactional" region="CodeMaster" />


<key column="CODE_MASTER_ID"/>
<one-to-many class="com.sony.spe.ifds.domain.CodeAttribute"/>
</set>


Full stack trace of any exception that occurs:
org.hibernate.LazyInitializationException: could not initialize proxy
- the owning Session was closed
at org.hibernate.proxy.AbstractLazyInitializer.initialize()V(AbstractLazyInitializer.java:53
) at org.hibernate.proxy.AbstractLazyInitializer.getImplementation()Ljava.lang.Object;(Abstrac
tLazyInitializer.java:84) at org.hibernate.proxy.CGLIBLazyInitializer.intercept(Ljava.lang.Object;Ljava.lang.reflect.M
ethod;[Ljava.lang.Object;Lnet.sf.cglib.proxy.MethodProxy;)Ljava.lang.Object;(CGLIBLazyInitializer.java:134)


Name and version of the database you are using:Oracle 9i

using second level cache doesnt mean it wont need a session . when u query a cached data , the session is involved in retrieving the object even if it is cached . ie, the caching is not independent , but related to session only . but the data will be loaded from cache if it is availabe in the secondary cache .

but second level cache is working for the parent class. What might be the reason for this ? Its not throwing this exception

please provide the code you are using to retrieve the parent and child from the cache .

http://www.hibernate.org/hib_docs/v3/reference/en/html_single/#performance-sessioncache

Two queries :

1. So, knowing this what is the suggested idiom for working with lazy second-level cached objects?

For example, using the Open Session In View pattern once the request, and thus session, has completed you may now have entities in the second-level cached which are proxied.

On a subsequent request, if you'd cached those entities on the client side, you'd have to manually re-associate the object via Session.Lock() to the current session in order to properly lazy load it from the second-level cache.

Does that make sense? Assuming the above is correct, which is fine, can anyone suggest a cleaner approach? I mean is this done typically through some interceptor or home-grown aspect?

2. Given a parent object that has lazy collections in the second-level cache, is it suffice to lock the parent only?

Cheers,
Roll

Inquiring minds want to know! :D