[hibernate-issues] [Hibernate-JIRA] Issue Comment Edited: (HHH-6880) Implementations of org.hibernate.type.Type contain references to non-serializable entities

Implementations of org.hibernate.type.Type contain references to non-serializable entities ------------------------------------------------------------------------------------------ Key: HHH-6880 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-6880 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.6.7 Environment: Seen this on MySQL but I believe this is environment-agnostic Reporter: Mindaugas Žakšauskas Priority: Critical Labels: hibernate This is a spin-off from - https://forum.hibernate.org/viewtopic.php?f=1&t=1013687&sid=e62b8... - http://stackoverflow.com/q/8404559/7345 org.hibernate.cache.CacheKey is an object which is used for L2 cache notifications - e.g. to flush a cache on a different cluster node when a certain object has been updated. The problem comes from org.hibernate.cache.CacheKey carrying the type which (sometimes) happens to have a reference to objects like org.hibernate.impl.SessionFactoryImpl. This problem is actually not just theoretic but also causes real pain. First, it takes much longer to broadcast cache flush events. Secondly, I get this exception during deserialization of such a CacheKey: java.lang.NullPointerException at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768) at org.hibernate.impl.SessionFactoryObjectFactory.getNamedInstance(SessionFactoryObjectFactory.java:159) at org.hibernate.impl.SessionFactoryImpl.readResolve(SessionFactoryImpl.java:753) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at java.io.ObjectStreamClass.invokeReadResolve(ObjectStreamClass.java:1061) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1762) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readUnshared(ObjectInputStream.java:441) at my.class.deserializeKey(EhcacheUtils.java:35) I have done a quick scan through all the types, and found these problems related to their serializability: 1) org.hibernate.type.CollectionType, org.hibernate.type.ComponentType and subclasses of both - they use attribute "typeScope" (of type TypeFactory.TypeScope) which is assigned in the constructor and kept in the but seems to be never used. The typeScope in turn has a reference to the SessionImpl. Can it simply be removed? 2) org.hibernate.type.EntityType (and its subclasses) stores typeScope and only uses it in the getter, so I guess it should be safe to remove it, too. 3) org.hibernate.type.SortedSetType and org.hibernate.type.SortedMapType keeps a reference to the comparator, but does not enforce its serializability. It should at least throw a runtime exception in org.hibernate.mapping.Collection::getComparator if the comparator is not serializable.