Any workaround to avoid the "getEntity" problem ?

yannraoul · **Posted:** Mon Dec 15, 2003 10:33 am

Hi all,

I would like to avoid loading dependent objects to save persistent objects...and i am looking for a safe procedure (without any side_effects) to do that.

Here is my new problem, still around the sessionImpl.getEntity private method.

Here is my case:

Model:
Object A <---n--------1---->Object B

Use case:
I want to save a new Object A with the corresponding object B, then displaying the list of Object A (with the title of object B), as follow:

ObjectA.id | ObjectA.name | ObjectA.ObjectB.title

Procedure:
- I create a new Object A (new)
- I create an Object B (existing in the database) with the new method
- I do objectA.setObjectB(myObjectBWithOnlyId)
- I save objectA - This runs perfectly in my case.
- I load all objectA to display the list - ths works except I don't get the ObjectB title, because the used object is the one I set during the setObjectId method...without title.

Question : Have I to load the objectB instance from Hibernate (quite heavy object) ? Are there any parameter to avoid "old" objects ?

Are there other workarounds (except doing a redirect between the save and the displayList methods) ???

Please help.
Yann

yannraoul · **Posted:** Tue Dec 16, 2003 4:43 am

anybody for a little help ?

yannraoul · **Posted:** Fri Dec 19, 2003 10:29 am

Hey, everyone has gone to turkey-hunt ? ;-)

emmanuel · **Posted:** Fri Dec 19, 2003 1:38 pm

yannraoul wrote:

Question : Have I to load the objectB instance from Hibernate (quite heavy object) ?

What about

Code:

select a.id, a.name, a.b.title from ObjectA a

yannraoul wrote:

Are there any parameter to avoid "old" objects ?

Can't follow you, what do you mean by old object

yannraoul · **Posted:** Fri Dec 19, 2003 1:51 pm

The "old" object is the one used in the following code from Hibernate source 2.0.3.

I mean it is an "already-existing-object-in-the-hibernate-local-repository (not cache)".

Code:

private Serializable doSave(Object object, Serializable id) throws HibernateException {
      
      ClassPersister persister = getPersister(object);
      
      Key key = null;
      final boolean identityCol;
      if (id==null) {
         if ( persister.isIdentifierAssignedByInsert() ) {
            identityCol=true;
         }
         else {
            throw new AssertionFailure("null id");
         }
      }
      else {
         identityCol=false;
      }
      
      if ( log.isTraceEnabled() ) log.trace( "saving " + MessageHelper.infoString(persister, id) );
      
      if (!identityCol) {   // if the id is generated by the database, we assign the key later
         key = new Key(id, persister);
         
         Object old = getEntity(key);
         if (old!= null) {
            if ( getEntry(old).status==DELETED ) {
               flush();
            }
            else {
               throw new HibernateException(
                  "The generated identifier is already in use: " +
                  MessageHelper.infoString(persister, id)
               );
            }
         }
         
         persister.setIdentifier(object, id);
      }
      

emmanuel · **Posted:** Fri Dec 19, 2003 1:56 pm

evict it first