attaching transient object with parent and dtos

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

I have a two objects ReleaseDBO and ProjectDBO (DBO=DatabaseObject) and I have a DTO ReleaseDTO that contains the release id and project id.

I am trying to implement a method that will save new ones or existing ones like saveOrUpdate().

My first try was to create a detached instance and merge it like so....

Code:

ReleaseDBO rel = Converter.convert(releaseDto);
           
ProjectDBO project = session.load(ProjectDBO.class, releaseDto.getProjectId());
            
project.addRelease(rel);

session.merge(rel);

Naturally, this complains about persisting a detached instance because of project.addRelease(rel);

I also cannot do the following code because a release has to have a project(not-null constraint) and so this fails during commit

Code:

ReleaseDBO rel = Converter.convert(releaseDto);

session.update(rel);
            
ProjectDBO project = session.load(ProjectDBO.class, releaseDto.getProjectId());

project.addRelease(rel);

Next, I thought of loading first but this is really bad because now my version is not used and compared for validity......

Code:

           ReleaseDBO rel = Db.get().get(ReleaseDBO.class, releaseDto.getId());
           if(rel == null)
              rel = new ReleaseDBO();
            Converter.convert(releaseDto, rel);
           
            ProjectDBO project = Db.get().load(ProjectDBO.class, releaseDto.getProjectId());
            project.addRelease(rel);

So to go over what I am trying to do again....
1. I would like to save new Releases
2. I would like to save changes to old Releases
3. I have to add a release to a project since every release must have an instance of a project(this is what causes most of my problems)

The only solution I can get so far is the last one above BUT with the addition of my own version checking which seems kind of ugly. Is there a better way to do this?
thanks,
dean

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

anyone know the answer?????

pasha · **Joined:** Sat Nov 27, 2004 4:13 am **Posts:** 137

Why do you have a DTO and a DBO?

Can't you have just one of them, with a private default constructor (which can be used by hibernate), and a public argumented constructor for your use?

pasha · **Joined:** Sat Nov 27, 2004 4:13 am **Posts:** 137

Why do you have a DTO and a DBO?

Can't you have just one of them, with a private default constructor (which can be used by hibernate), and a public argumented constructor for your use?
-----------------------

DON'T FORGET THE CREDITS

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

No, I can't. The product is using Jaxme which generates the DTO's and the DBO's represent the domain better than the DTO's do.

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

does no one have a cleaner solution than mine????? pleeeaaase help!!!

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

anyone???? would love to see a better solution than this?

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

anyone? a reply with this is impossible would be nice as well.

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

I think this may be a bug as I believe the data that is in the cache should be that of my projDbo bean instead of the data from the database. Either that or I have to program some real ugly code here to compare versions and stuff (or write a save method and an update method separately).

private ProjectDto updateOrSave(ProjectDto projectDto)
{
ProjectDBO projDbo = convert(projectDto);

Session session = openSession();
try {
session.getTransaction().begin();

//session.saveOrUpdate(projDbo);
FolderDBO folder = (FolderDBO)session.load(FolderDBO.class, projectDto.getFolderId());

//this method causes the folder and projDBO from database to load into cache. The projDBO
//in the cache has the values of the database not the projDbo values from projDbo
//this method causes the folder and projectDbo from database to load into cache. The projDBO
//in the cache has the values of the database the values of the projDbo variable being passed in here.....
//I am referring to session's StatefulPersistenceContext which has a map of entitiesByKey and
//after this method is called, 2 values exist...one FolderDBO and one ProjectDBO
folder.addChildProject(projDbo);

//session.merge(projDbo);
session.saveOrUpdate(projDbo);

session.getTransaction().commit();
} finally {
session.close();
}

return convert(projDbo);
}

deanhiller · **Joined:** Thu Sep 16, 2004 4:56 pm **Posts:** 80

NEVER MIND, YEAH!!!! got it. I had a method trying to follow the hibernate pattern for updating both ends of the association.....

Code:

   public void addChildProject(ProjectDBO childProject) {
      if(childProject == null)
         throw new IllegalArgumentException("requirement may not be null and was");
      else if(getChildProjects().contains(childProject))
         return; //we only allow it to be added once
      else if(childProject.getParent() != null) {
         //make sure we reattach the release we are removing to the session...
         childProject.getParent().removeChildProject(childProject);
      }
      
      childProject.setParent(this);
      getChildProjects().add(childProject);
   }

Looks fine and all, but getChildProjects().contains(childProject) was loading the childProject from the database. Once I get rid of that if statement, everything works great. Thanks to a debugger and just stepping through the hibernate code!!!
sweet,
dean