Reading from persisted TreeCacheAop leads to InstantiationEx

[motormind]

I pretty much ironed out most of the problems I have with the TreeCacheAop-implementation by delaying reading the cache after an event as much as possible., One thing remains though: when I try to read a persisted cache I get this error:

Caused by: org.jboss.util.NestedRuntimeException: failed creating instance of nl.motormind.ToCCommand; - nested throwable: (java.lang.InstantiationException: nl.motormind.ToCCommand); - nested throwable: (org.jboss.cache.CacheException: failed creating instance of nl.motormind.ToCCommand; - nested throwable: (java.lang.InstantiationException: nl.motormind.ToCCommand))
 at org.jboss.cache.aop.collection.CachedMapImpl.get(CachedMapImpl.java:59)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.jboss.cache.aop.collection.CollectionInterceptorUtil.invoke(CollectionInterceptorUtil.java:122)
 at org.jboss.cache.aop.collection.CachedMapInterceptor.invoke(CachedMapInterceptor.java:108)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:98)
 at AOPClassProxy$0.get(AOPClassProxy$0.java)
 at nl.mindef.c2sc.titaan.tbl.server.TblServerRmt.getStoredCommands(TblServerRmt.java:606)
 at nl.mindef.c2sc.titaan.tbl.server.TblServerRmt.getCommands(TblServerRmt.java:618)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
 at sun.rmi.transport.Transport$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at sun.rmi.transport.Transport.serviceCall(Unknown Source)
 at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
 at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
 at java.lang.Thread.run(Unknown Source)

I am using the FileCacheLoader for persisting the cache. Now I do get the idea that the code bails since the FileCacheLoader expects a default constructor when loading a POJO from the cache. Is this correct?

[ben.wang]

Yeah, if you have overloaded your constructor you need to provide a default one as well.

-Ben

[motormind]

Yeah, if you have overloaded your constructor you need to provide a default one as well.

-Ben

When I define default constructors, I don't get an InstantiationException anymore... but now I get NullpointerExceptions, since certain values have not been filled. It does strike me as rather odd that the classes get instantiated once more... shouldn't it be enough to simply serialize and deserialize them?

[motormind]

Okay, let me put it a bit more straightforwad: is is possible to use a CachelLoader with TreeCacheAop? If yes, how? Simply putting on the option doesn't work, obviously. If no, what did I miss in the manual?

[ben.wang]

Sorry to reply back late. I am in the process of relocating back to Taipei. :-)

Yes, it is possible. But I need help here to reproduce your problem so I can fix the bug (if there is one). It should be easy for you to cook up a simple JUnit test case that illustrates the problem instead of me trying to reproduce it, don't you agree?

Thanks,

-Ben