I'm trying to use order-by sorting to create a SortedSet, but I'm getting IllegalArgumentExceptions, saying that my set is of type PersistentSet, not SortedSet. Using sort="natural" works fine, but I can't get it to work using "order-by".

The following is the stack trace for setting a set, but I also get errors loading a set if it's already in the database.

Hibernate version:
3.2.5

Mapping documents:

<class name="testhibernate.A" table="A">
<id name="id">
<generator class="native"></generator>
</id>
<set name="mySet" cascade="all" order-by="value">
<key column="A_id" />
<one-to-many class="testhibernate.B" />
</set>
</class>
<class name="testhibernate.B" table="B">
<id name="id" column="B_ID">
<generator class="native"/>
</id>
<property name="value" />
</class>

Code between sessionFactory.openSession() and session.close():

Transaction tx = session.beginTransaction();

//Create and save an A.
A a = new A();
session.save(a);
session.flush();

//Create and save two B's
B b1 = new B();
B b2 = new B();
b1.setValue(new BigDecimal(11) );
b2.setValue(new BigDecimal(12) );
session.save(b1);
session.save(b2);
session.flush();

//Add these B's to the A.
SortedSet<B> s = new TreeSet<B>();
s.add(b1);
s.add(b2);
a.setMySet(s);

tx.commit();


Full stack trace of any exception that occurs:

Exception in thread "main" org.hibernate.PropertyAccessException: IllegalArgumentException occurred while calling setter of testhibernate.A.mySet
at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:104)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.setPropertyValues(AbstractEntityTuplizer.java:337)
at org.hibernate.tuple.entity.PojoEntityTuplizer.setPropertyValues(PojoEntityTuplizer.java:200)
at org.hibernate.persister.entity.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:3566)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:133)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:196)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:76)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:26)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at testhibernate.Test.main(Test.java:34)
Caused by: java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:42)
... 11 more

Name and version of the database you are using:

mysql, 5.0.45

The generated SQL (show_sql=true):

18:02:39,580 DEBUG SQL:401 - insert into A values ( )
18:02:39,618 DEBUG SQL:401 - insert into B (value) values (?)
18:02:39,619 DEBUG BigDecimalType:133 - binding '11' to parameter: 1
18:02:39,621 DEBUG SQL:401 - insert into B (value) values (?)
18:02:39,622 DEBUG BigDecimalType:133 - binding '12' to parameter: 1

Debug level Hibernate log excerpt:

18:04:28,965 DEBUG AbstractFlushingEventListener:154 - dirty checking collections
18:04:28,965 DEBUG AbstractFlushingEventListener:171 - Flushing entities and processing referenced collections
18:04:28,976 DEBUG WrapVisitor:87 - Wrapped collection in role: testhibernate.A.mySet
18:04:28,976 ERROR BasicPropertyAccessor:94 - IllegalArgumentException in class: testhibernate.A, setter method of property: mySet
18:04:28,977 ERROR BasicPropertyAccessor:98 - expected type: java.util.SortedSet, actual value: org.hibernate.collection.PersistentSet

If I change the <set> tag to include both order-by="value" and sort="natural", I do not get the same error. The SQL is correct, it uses order-by; however, it of course sorts it afterward in java, which I was trying to avoid.

.hbm.xml:

SQL: