Hi All,

I would want to know what is ideal implementation in real world scenarios.

Is it a popular practice to have one Hibernate DAO (entity based) per Hibernate Domain object or we can have a few DAO's (functionality based) catering to multiple Hibernate Domain objects.

When to adopt which approach is what we are looking at the moment.

Do post you comments on the same.


Regards,

A personal favourite of mine at the moment, is to have a data object for all your domain objects which you then extend so you can add any additional functionality. This is handy because it means you can regenerate your hibernate objects from the database when you need to make schema changes without loosing any custom code you might of written for your domain objects.
With regards to the DAO layer -- I choose to have a <TableName>DAO Interface which extends a HibernateDAOMethods<<TableName>> Interface (this has all the standard methods from HibernateDaoSupport), a <TableName>DAOBaseHibernate which extends Spring's HibernateDaoSupport, and then finally a <TableName>DAOHibernate class that extends my <TableName>DAOBaseHibernate and implements my <TableName>DAO Interface.
It sounds complicated but it's actually quite nice. What I means is that you can keep your auto generated DAOBaseHibernate separated from any custom code you write, again handy if you do a regen from your database after schema changes.
I’m using this pattern for my Job that I’ve been working on for the past year and it works really well. I’ve also recently adopted it for a new project I’m working on for my own personal interest.

Hope that helps.

Hi Adamgibbons,

Thanks for your response. That indeed was very helpful.

What I gathered from your response is you are auto-generating Domain objects per table & create pojo's extending these domain objects so any custom code we have in our custom domain objects will not be impacted by changes to the underlying database table structure.

Also you mention auto-generating DAO's that what I have not heard of. Could you ellaborate a bit more on the same.



Regards,

I think you or I have confused Domain Objects / POJOs / DAOs.
When I think of a Domain object it is just a class that extends a Hibernate generated POJO, also could be called Data Object.
DAOs are what I call the Hibernate "Home" obecjts, these are made with the <hbm2dao /> ant task.
They are your data layer that lets you find a Domain Object (POJO) by ID for example or save a new one.
This is just my personal preference and what we use on our project, I'm sure there are lot's of other ways you can do it or other terms you can give things.