Lazy initialization problem, I'm not sure...

Krieger · **Joined:** Mon Oct 18, 2004 12:29 pm **Posts:** 8

Hello everyone,
I posted a topic regarding a weird behavior with a property. I explained that if earlier in the code I made some call like System.out.println(obj.getForward()); the system worked perfectly, otherwise, my struts app would crash later on in a jsp because obj.getForward() returned null (where in fact It isn't null). I thought (and a reply came with the same answer), that it had to do with the lazy initialization of the object. The problem is that the property I'm talking about is a String not a collection, and as far as I know, lazy fetching of individual properties is default to false. (paranoid as I am, I set it to false, and still the same result). Here is the mapping of the Privilege class and others.

Code:

<hibernate-mapping>
   <class name="MPrivilege" table="T_PRIVILEGE">
      <id name="id" type="int" unsaved-value="0">
         <generator class="increment"/>
      </id>

      <property name="name"/>
      <property name="forward"/>

      <bag name="rolPrivilegios" inverse="true" lazy="true" cascade="all-delete-orphan">
         <key column="privilege_id"/>
         <one-to-many class="MRolPrivilege"/>
      </bag>
   </class>
</hibernate-mapping>

<hibernate-mapping>
   <class name="MRolPrivilege" table="T_ROL_PRIVILEGE">

      <id name="id" type="int" unsaved-value="0">
         <generator class="increment"/>
      </id>

      <many-to-one name="privilegioRef" class="MPrivilege" column="privilege_id"/>
                 <many-to-one name="rolRef" class="MRol" column="rol_id"/>
   </class>
</hibernate-mapping>

<hibernate-mapping>
   <class name="MRol" table="T_ROL">

      <id name="id" type="int" unsaved-value="0">
         <generator class="increment"/>
      </id>

      <property name="nombre"/>

      <bag name="rolPrivilege" inverse="true" lazy="true" cascade="all-delete-orphan">
         <key column="rol_id"/>
         <one-to-many class="MRolPrivilege"/>
      </bag>      
   </class>
</hibernate-mapping>

On a Struts Action this is the relevant code

Code:

Iterator itt = rol.getPrivileges().iterator();
        while (itt.hasNext()) {
          MPrivilege privilege = (MPrivilege) itt.next();
          menuElements.add(privilege);
        }

And finally in a jsp I iterate through menuElements vector, and print the privelege.getForward().
Any help is appreciate it
Thanx in advance.

kdekooter · **Joined:** Mon Apr 12, 2004 6:33 pm **Posts:** 35

I had the same problems after migrating to hibernate 3. I set lazy="false" on the class tag (I don't see this in your mapping). Althought the docs say this is the default it solved the problem for me.

pksiv · **Posted:** Fri Jul 29, 2005 9:08 pm

kdekooter wrote:

I had the same problems after migrating to hibernate 3. I set lazy="false" on the class tag (I don't see this in your mapping). Althought the docs say this is the default it solved the problem for me.

lazy="false" at the class-level is NOT the default in Hibernate 3.

Hibernate 3 changed the default to lazy=true for associations so that we (users) are forced to think about what associations we need and don't perform any necessary database access.