SCEA and EJB 3.0

[D. Rose]

DTO pattern which is used in EJB 2.0 is branded as antipattern in EJB 3.0
so should it be used in assignment at all?

[Ramon Gill]

Hi D,
Haven't read much about EJB 3.0, but won't we still need DTO's to transfer data to the Web Tier?

Also, does anti-pattern mean its supposed to be a bad thing?

Ray

[Damian FRACH]

IMO:

1) EJB 3.0 is not still finished, so it can not be required by anybody

2) DTP is usefull for remote calls to reduce traffic and so on ...
if it is not required you should not use remote calls between web and business tiers

if you need to cluster you still should use web and business tier in the same JVM and cluster horizontally with sticky sessions and web server load balancer

[Damian FRACH]

IMO:

anti-pattern means that the idea was promoted as a good thing, but lately was found that it is an evil ... ))

[Billy Tsai]

its like antiproton and antimatter

[Francis Shillitoe]

A pattern is a description of a GOOD practice which has been used in several scenarios.

An anti-pattern is description of a BAD practice which has been used in several scenarios

[Ramon Gill]

Hi all,
Why is DTO an anti-pattern in EJB 3.0 ?
Ray

[Paul Mukherjee]

Originally posted by Ramon Gill:
Hi all,
Why is DTO an anti-pattern in EJB 3.0 ?
Ray

EJB 3.0 proposes a transparent approach to persistence. That is, entity beans are plain old Java objects supplemented with annotations that a persistence manager will use to persist the bean. Since the entity bean itself is a plain old Java object, there is no need to use a data transfer object.

I guess that in EJB 3.0 they have tried to remove the need for DTOs. Therefore use of them would be an anti-pattern.

Paul

[Ramon Gill]

Hi Paul,
I get it about persistence and POJO's. I still don't understand how you can do away with DTO's though. How do you transfer data between tiers? Are they proposing local interfaces for everything?

Still confused.

Ray

[Paul Mukherjee]

Originally posted by Ramon Gill:
Hi Paul,
I get it about persistence and POJO's. I still don't understand how you can do away with DTO's though. How do you transfer data between tiers? Are they proposing local interfaces for everything?

Still confused.

Ray

You just pass the POJOs around as serializable objects.

Paul