hi there,

i cannot get the dom4jsession to load/import xml file into my database.

Hibernate version:
3

i have a class user that has a collection of roles.
i have an xml file with a bunch of users in it like this:

<Users>
<User>
<userId>admin</userId>
<firstName>adminFirst</firstName>
<lastName>adminLast</lastName>
<password>sof</password>
<roles>
<Role>admin</Role>
<Role>manager</Role>
</roles>
</User>

Session session = HibernateUtil.currentSession();
Session dom4jSession = session.getSession(EntityMode.DOM4J);
SAXReader reader = new SAXReader();
InputStream is = ...
Document document = reader.read(is);
Element root = document.getRootElement();

for ( Iterator i = root.elementIterator("User"); i.hasNext(); ) {
Element userElement = (Element) i.next();
dom4jSession.save("com.foo.User", userElement);
}

session.commit();

Full stack trace of any exception that occurs:
java.lang.ClassCastException: org.dom4j.tree.DefaultElement
at org.hibernate.event.def.DirtyCollectionSearchVisitor.processCollection(DirtyCollectionSearchVisitor.java:51)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:101)
at org.hibernate.event.def.AbstractVisitor.processValue(AbstractVisitor.java:61)
at org.hibernate.event.def.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:55)
at org.hibernate.event.def.DefaultFlushEntityEventListener.hasDirtyCollections(DefaultFlushEntityEventListener.java:404)
at org.hibernate.event.def.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:392)
at org.hibernate.event.def.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:181)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:104)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:195)
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:870)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:349)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)


any help is greatly appreciated.

thanks.

I am using hibernate 3.0.5 and I can import/export sucessfully. Firstly, I imagine your database is empty when you are importing?
Map the user-role joint table to be as follows;



This will include the parent user & role entities into your user-role joint object xml.
In User and Role object mapping make sure you have turned off the xml using embed-xml="false".
When import, make sure that you import in the sequence of User, Role and User-Role. Also, user the session.replicate() to do the insert or update to the database. Hope this help you.

yes, my db is empty when importing. i am using hibernate 3.1rc3. not sure if that makes a difference. i looked at the source code where the exception was thrown, it's looking for a persistent collection and my object is a dom4j element. maybe the code is broken somehow?

i am loading roles first, followed by session flush, then loading users.

below is my mapping file:

user:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="com.foo.User"
table="fos_user"
>

<id
name="userId"
column="user_id"
type="java.lang.String"
length="256"
>
<generator class="assigned">
</generator>
</id>

<property
name="firstName"
type="java.lang.String"
update="true"
insert="true"
column="first_name"
length="64"
/>

<property
name="lastName"
type="java.lang.String"
update="true"
insert="true"
column="last_name"
length="64"
/>

<property
name="password"
type="java.lang.String"
update="true"
insert="true"
column="password"
length="64"
/>

<set
name="roles"
table="fos_user_roles"
lazy="false"
cascade="none"
sort="unsorted"
>

<key
column="user_id"
>
</key>

<many-to-many
class="com.foo.Role"
column="user_role"
outer-join="auto"
embed-xml="false"
/>

</set>
</class>

</hibernate-mapping>


role:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="com.foo.Role"
table="fos_role"
lazy="false"
>
<id
name="name"
column="name"
type="java.lang.String"
length="64"
>
<generator class="assigned">
</generator>
</id>
<property
name="description"
type="java.lang.String"
update="true"
insert="true"
column="description"
length="256"
/>
</class>
</hibernate-mapping>

i found the problem: my classes use optimistic locking. that's why DirtyCollectionSearchVisitor is in the stack trace. i tried to remove optimistic locking. the code works now. but i really need versioned objectsl. could someone provide a quick fix?

ps in the hbm snippet in my original post, i deleted optimistic locking 'cause i thought it's noise. apparently it's not. [/quote]

Can't you use the <version> tag in the mapping file.



This will version your objects automatically.

that's right. but with a versioned object, saving xml will fail. you can try it with your application where there is a class with a one-to-many (collection) relationship to another class, both are versioned.

my mapping files are the following:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="com.foo.User"
table="fos_user"
optimistic-lock="version"
>

<id
name="userId"
column="user_id"
type="java.lang.String"
length="256"
>
<generator class="assigned">
</generator>
</id>

<version
name="version"
column="version"
type="int"
/>

<property
name="firstName"
type="java.lang.String"
update="true"
insert="true"
column="first_name"
length="64"
/>

<property
name="lastName"
type="java.lang.String"
update="true"
insert="true"
column="last_name"
length="64"
/>

<property
name="password"
type="java.lang.String"
update="true"
insert="true"
column="password"
length="64"
/>

<set
name="roles"
table="fos_user_roles"
lazy="false"
cascade="none"
sort="unsorted"
>

<key
column="user_id"
>
</key>

<many-to-many
class="com.foo.Role"
column="user_role"
outer-join="auto"
/>

</set>
</class>

</hibernate-mapping>


<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping
>
<class
name="com.foo.Role"
table="fos_role"
lazy="false"
optimistic-lock="version"
>
<id
name="name"
column="name"
type="java.lang.String"
length="64"
>
<generator class="assigned">
</generator>
</id>
<version
name="version"
column="version"
type="int"
/>
<property
name="description"
type="java.lang.String"
update="true"
insert="true"
column="description"
length="256"
/>
</class>
</hibernate-mapping>

No, I have the same situation as yours but it works fine. However, I had a problem with many-tomany relationship when generating the xml. So, I changed it to include the extra mapping for user-role and put two many-to-one relationships for Role and the User. Have a look at the other changes I have done in your following mapping. Take note that I have removed your many-to-many relationship.
By the way, I thought you got rid of "optimistic-lok". Anyway,

thanks for the reply. i meant in my post that it failed with a many-to-many relationship, which is what i have. i was able to export to xml with no problem. but importing the xml back to hibernate gave me the classcastexception in DirtyCollectionSearchVisitor. like i said, if i comment out the optimistic locking/version part, then it would work.

i think i will file a bug when i get some time: importing xml to a versioned class that has a many-to-many relationship to another class throws class cast exception.


[quote="firebug"]No, I have the same situation as yours but it works fine. However, I had a problem with many-tomany relationship when generating the xml. So, I changed it to include the extra mapping for user-role and put two many-to-one relationships for Role and the User. Have a look at the other changes I have done in your following mapping. Take note that I have removed your many-to-many relationship.
By the way, I thought you got rid of "optimistic-lok". Anyway,