Possible solutions for NonUniqueObjectException

diegoman · **Joined:** Wed Mar 24, 2004 6:18 am **Posts:** 15

Hi! I've had some problems recently with NonUniqueObjectException's (a different object with the same identifier value was already associated with the session). The problem is that I'm using the method copyProperties of class BeanUtils to perform the conversion "persistent object->bean->persistent object". After executing this method, the object identifier of the nested objects is lost (I'm using converters, which create new instances, to convert nested objects) and when I try to update a persistent object I get the aforementioned exception.

I have a workaround for this but it's not generic nor "elegant", so I'd like to know how do you manage this situation.

Thanks in advance,
Diego

shl · **Posted:** Mon Aug 23, 2004 11:05 am

http://forum.hibernate.org/search.php?mode=results&search_keywords=NonUniqueObjectException

diegoman · **Joined:** Wed Mar 24, 2004 6:18 am **Posts:** 15

Thanks, but I had already searched the forum, and I really think I've read all the messages about this topic.

shl · **Posted:** Mon Aug 23, 2004 11:28 am

diegoman wrote:

Thanks, but I had already searched the forum, and I really think I've read all the messages about this topic.

I don't think anybody could help... I don't see your mappings and java code.
I could only suggest you to avoid the following practice (but if you have searched the forum you should know this):

Code:

obj = (MyClass) session.get(id);
obj.setProperty1(value); // modify the object
//session.update(obj) // DON'T  DO THIS, the obj is already associated with the session and should be saved/update

diegoman · **Joined:** Wed Mar 24, 2004 6:18 am **Posts:** 15

OK, I didn't put code because I thought it wasn't neccessary in this case, but here it is:

<hibernate-mapping>
<class name="MyClass" table="my_class">
<id
name="id"
type="java.lang.Long"
column="id">
<generator class="native" />
</id>
<property
name="oneProperty"
type="java.lang.String"
column="one_property"
length="10"/>
<many-to-one
name="nestedObject"
class="NestedObject"
not-null="true"
cascade="all">
<column name="id_nested_object" />
</many-to-one>
</class>
</hibernate-mapping>

<hibernate-mapping>
<class name="NestedObject" table="nested_object">
<id
name="id"
type="java.lang.Long"
column="id">
<generator class="native" />
</id>
<property
name="anotherProperty"
type="java.lang.String"
column="another_property"
length="10"/>
</class>
</hibernate-mapping>

Java code:

myObject = ses.load(myClass, some_id);
BeanUtils.copyProperties(myBean,myObject);
myBean.setOneProperty('mec');
myBean.getNestedObject().setAnotherProperty('mic');
BeanUtils.copyProperties(myObject,myBean);//PROBLEM: here, a new Instance of nestedObject has been created; the old reference it's been lost
ses.saveOrUpdate(myObject); //NonUniqueObjectException on nestedObject; tried with saveOrUpdateCopy but didn't work because of this, I think: http://forum.hibernate.org/viewtopic.ph ... texception