Serialization problem using JDBC cache loader and MySQL

[drcallaway]

I am running into a problem when deserializing objects stored in the JBoss Cache via the JDBC cache loader. I can start the cache, load objects into it, and read objects from it without a problem. The objects that I have stored in the cache specifically set the serialVersionUID variable to 1. This all works fine until I shutdown and restart the cache. At this point, I get this error when attempting to access a node:

[JDBCCacheLoader] Failed to load node for fqn /mynode java.lang.Exception:
Unable to load to deserialize result:
Caused by: java.io.InvalidClassException: com.company.generated.MyNode; local class incompatible:
stream classdesc serialVersionUID = 1, local class serialVersionUID = -7258818124315218931

According to this error, it looks like the version of the class stored in the database has a UID of 1 (which is correct). However, it then indicates that the local class has a UID of -7258818124315218931. Why is JBoss generating a UID when the local class already specifies a serialVersionUID of 1? After all, it was the exact same version of this local class that was stored in the cache to begin with.

Any suggestions are appreciated.

Thanks!

Dustin

[brian.stansberry]

Are you saying you made serialVersionUID a mutable field and are setting it to one on some instances of the class? That won't work; the java io classes (not JBoss) compare the value read from the stream to the value of the Class object.

[drcallaway]

No, it is not mutable. The serialized classes contain this code generated by the JAXB compiler:

private final static long serialVersionUID = 1L;

The classes seem to be getting stored with this UID but not extracted that way.

[brian.stansberry]

I suspect you have different versions of the class on the classpath.

Caused by: java.io.InvalidClassException: com.company.generated.MyNode; local class incompatible:
stream classdesc serialVersionUID = 1, local class serialVersionUID = -7258818124315218931

JBoss is not generating that local class serialVersionUID = -7258818124315218931; that comes from the JRE, which must be seeing a different version of the class.

[drcallaway]

Yep. You nailed it. I discovered that I had an old version of the WAR file still in JBoss's deploy directory. Somehow JBoss was inserting the newer file into JBC but using the older class when pulling it out. I removed the old WAR file and everything seems to be working fine. Thanks!