Can I use Builder Pattern for creating Entities?

[Nilessh Ganu]

In my assignment, one of the Entity should be created with data which would be (combination of partly data from 2 entities).
To combine the data and set few more Entity specific data, I am planning to use Builder pattern in SLSB.
Is this a common practice or should be avoided?

If allowed, can I use it like this:

@stateless
class EntityAManagerBean implements EntityAManager {

       void createEntityA(){
            // calling builder and director from here
       }
}

class EntityDirector {
     BuilderIf builderIf;

     void constructEntityA(EntityB, EntityC){       
            builderIf.buildEntityA(EntityB, EntityC);
            // may be some more additions
     }

}

interface builderIf{
     void buildEntityA(EntityB, EntityC);
}

class EntityABuilder implements builderIf{
     void buildEntityA(EntityB, EntityC){
            // instantiating TargetEntity EntityA here

     }
}

So I end up instantiating the entity in the builder. Is that acceptable ?

[Nilessh Ganu]

JPA entities are simply java objects until in "managed" state by EntityManager.
So do applying builder pattern for it, sounds okay ? A simple YES/NO would be appreciated.