Hello anyone out there.

I have a basic many to many question.

I have th cat class of the quickstart.

And made a CatPound class. o try to save a collection of cats.

public class CatPound {

private String id;

private Collection cats;

private String name;

....
public CatPound(){
cats = new Vector();
}

------------------------------------

the Catpound.hbm.xml goes:

<hibernate-mapping>
<class name="hbtest.CatPound" table="CATPOUND">
<!-- A 32 hex character is our surrogate key. It's automatically
generated by Hibernate with the UUID pattern. -->
<id name="id" type="string" unsaved-value="null" >
<column name="CATP_ID" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id>
<!-- A cat has to have a name, but it shouldn' be too long. -->
<property name="name">
<column name="NAME" sql-type="varchar(16)" not-null="true"/>
</property>
<!-- <property name="sex"/>
<property name="weight"/>-->
<set name="cats" table="catpound-cat" cascade="all" lazy="true">
<key>
<column name="CATPID" not-null="true"/>
</key>
<many-to-many class="hbtest.Cat">
<column name="CATID" not-null="true"/>
</many-to-many>
</set>

</class>
</hibernate-mapping>

-----------------

When the SessionFactory is initiali<ing I get the following exception:

INFO: Mapping collection: CatPound.cats -> catpound_cat
java.lang.NoClassDefFoundError: org/odmg/DCollection
at java.lang.ClassLoader.defineClass0(Native Method)



-----------------

Ideas? hits? Are very much apreciated.

Thanks
Mata

If you want to map associations, the odmg.jar is a required library.

Oh! That was easy enough. Thanks for the swift answer.

But I now get a:

java.lang.ClassCastException
at net.sf.hibernate.type.SetType.wrap(SetType.java:27)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2519)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2459)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:708)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:605)
at net.sf.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:1202)
at com.b4.hbtest.ClaseParaProbar.SalvarColecciones(ClaseParaProbar.java:104)


when performing the save.

A Vector is not a Set.

Please use the interface types for collection valued properties and an implementation that is more "modern":

Set cats = new HashSet();

Ok, sorry. It's been a couple of years since I didn't work with Java. I guess old habbits do die hard.

I was meaning to avoid this, but I guess I have to look into Java Collections again.

thaks for your quick answers