I have the next 3 tables

Products
{
Id (PK)
Name
}

Component
{
Id (PK)
Name
}

ProductComp
{
ProductId
ComponentId
Details
Other1
Other2
Other3
}


The idea is that (ProductId & ComponentId) makes a composite primary key...

Can you give me an example of mapping these tables...Is it possible without a specific (dummy) composite class?...just using 3 classes in total

Also it will be niced to see an example using attributes and not xml files...But if it's possible only using xml and 3 mapping classes is ok.

Thx in advance

First, you should know that composite-id are not recommended. If possible, they must be avoided and only used because of legacy databases.

So, this said
* Absolutely no problem for what you want to do. Hibernate is able to handle the cases where a composite-id is represented by a specific composite class or only field in one object. Still, you will maybe like to know the best practice is to use a class to represent a compositeId. In fact, this makes easier reusability, for example in the case where you'd like to reference the same primary-key from a new other class.

* You will find the example in the reference documentation : http://www.hibernate.org/hib_docs/v3/re ... ompositeid
This doc is very thorough, don't hesitate to refer to it as often as necessary.