Hello,

I am using Hibernate 2.1.2, and am running into an odd problem. I have a class that has a Set of objects defined as composite-elements. There is no mapping document for the element, but there is a mapping file for the holding class. That snippet is:

<set
name="activities"
table="BUSINESS_ACTIVITIES"
lazy="true"
inverse="false"
cascade="all-delete-orphan"
sort="unsorted">

<key column="business_id"/>

<composite-element class="com.hic.eboss.Activity">

<property
name="type"
type="com.hic.eboss.ActivityType"
update="true"
insert="true"
column="type"/>

<property
name="started"
type="java.util.Date"
update="true"
insert="true"
column="started" />

</composite-element>
</set>

When I add some Activities into this object and try to save it, the correct SQL statements are generated, but an exception is thrown by hibernate:

net.sf.hibernate.MappingException: No persister for: com.hic.eboss.Activity
net.sf.hibernate.impl.SessionFactoryImpl.getPersister(SessionFactoryImpl.java:344)
net.sf.hibernate.impl.SessionImpl.getClassPersister(SessionImpl.java:2656)
net.sf.hibernate.impl.SessionImpl.getPersister(SessionImpl.java:2663)
net.sf.hibernate.impl.SessionImpl.isSaved(SessionImpl.java:2700)

Some of the debug log follows:

[DEBUG,net.sf.hibernate.collection.BasicCollectionPersister] Inserting rows of collection: [com.hic.eboss.Business.activities#402801e6fbebdad900fbebdda5c90005]
[DEBUG,net.sf.hibernate.impl.BatcherImpl] about to open: 0 open PreparedStatements, 0 open ResultSets
[DEBUG,net.sf.hibernate.SQL] insert into BUSINESS_ACTIVITIES (business_id, type, started) values (?, ?, ?)
Hibernate: insert into BUSINESS_ACTIVITIES (business_id, type, started) values (?, ?, ?)
.......
[DEBUG,net.sf.hibernate.collection.BasicCollectionPersister] done inserting rows: 3 inserted
[DEBUG,net.sf.hibernate.impl.BatcherImpl] done closing: 0 open PreparedStatements, 0 open ResultSets
[DEBUG,net.sf.hibernate.impl.BatcherImpl] closing statement
[DEBUG,net.sf.hibernate.impl.SessionImpl] post flush
[DEBUG,net.sf.hibernate.transaction.JDBCTransaction] commit
[DEBUG,net.sf.hibernate.impl.SessionImpl] flushing session
.......
[DEBUG,net.sf.hibernate.engine.Cascades] cascading to collection: com.hic.eboss.Business.activities
[DEBUG,net.sf.hibernate.transaction.JDBCTransaction] rollback
[DEBUG,net.sf.hibernate.impl.SessionImpl] transaction completion
[DEBUG,net.sf.hibernate.impl.SessionImpl] flushing session

It's very odd. The schemaexport tool creates the right DDL given the above mapping file, and Hibernate seems to be making the write SQL. Still, an exception is thrown.

Any ideas or tips?

Thanks very much!
Seth

After reading some of the document (great job, btw!), I thought I had a lead on the solution to this problem.

In Chapter 7, it states that if a Set has composite-elements, then none of the properties can be null. I am leaving one property null, so I thought that might be it. I changed the java.util.Set over to java.util.List, and then changed the hibernate collection to a bag. (I didn't choose list because there wasn't anything to order by)

Unfortunately, this does not help. I still receive the "No persister for" error.

Thanks,
Seth

I found out the problem. I had to remove the cascade="all-delete-orphan" attribute from the <set>.

I don't know if it's because I set cascade to something, or the value of all-delete-orphan was causing the problem.

Moral of the story, don't use cascade="all-delete-orphan" when you have a collection (set, bag, or list) of composite-elements.

Wonder how I get this into the documentation?

I think that this is expected, as a component/composite element has "pass by value" semantics, so an "orphan" can actually never exist, as a value type is always bound to the lifecycle of its containing/parent entity.

Yeah, it makes sense. The error message, though, makes debugging this problem very difficult.

Still, where would I send a patch to the documentation? This would be helpful information for others.

Thanks!

Post a JIRA issue, you don't have to provide a full patch for documentation (it has been updated for the next release anyway).