1. Domain driven design and jpa
Cecilio Álvarez Caules
Java Master Oracle Certified Enterprise Architect
web:

2. Domain Driven design (agenda)
Problems
Create
Model
Use
JPA

3. Domain model
problems

4. main Problems Expert Problem Communication Problem Complexibility

5. Experts People General Knowledge You dont know anything All
people looks
experts

6. communication problem

7. is a great football team
example
Barça
is a great football team
Pau
Gasol
not a football team
Barça
club
Football
team
club with a great team

8. Complexibility problem

9. It’s not so easy! Barça club Football team club and great team Barça
senior F 18
club and teams
Barça
club F
senior A F
senior B F 18
club and teams
Barça
club
Football
senior A men
Football
senior A women

10. summarizing Problems There is no easy access to experts
Communication can be tricky
Models are more complex than you think
It is your responsibility to create a good model
Knowing your customer proves to be essential

11. Agenda
Create
Model
Problems
Use
JPA

12. How to build solid models?

13. modeling my TALK How does Barcelona Java conferences works?
An expert gives a talk about a technical subject for Java Developers.

14. first model
Expert
name
Talk
title
duration 1 n
Developer
name n n

15. analisys Your model is wrong Is my model correct?
Case1 :Your model is bad ,You need to improve your model , you need more concepts.
Case 2: Your model is fine but small, you can go to next meeting
Your model is wrong

16. Analisys patterns
Places
Things
Roles
Events
Description

17. very OLD books Analisys patterns (Martin Fowler)
Java UML in Colour (Peter Coad)
Data Model Patterns (David Hay)

18. <Role> Expert 1 <Event> Talk n <Role> Developer n
name n 1
<Event>
Talk
title
duration
<Role>
Developer
name n

19. what an event is?
Point
TimeLine
Heart
of Model
Talk???
whats
happens?

20. working with talk Talk Talk Talk Presentation thing event repeat
duration
title
Talk
duration
title
date
Talk
duration
title
Presentation
date
thing
event
repeat

21. <Thing> <Role> Talk Expert <Place> Room
name
<Thing>
Talk
title
duration
<Place>
Room
number
<Event>
Presentation
date
<Role>
Developer
name

22. thinking about You have a problem with your customer
Maybe its not the correct person to talk
How we can solve/reduce this problem?

23. Models and Time
time line

24. models and events
before
after T T T
Enrollment
Presentation
Survey

25. before events Enrollment Presentation Conference <Thing> Talk
date
Presentation
Conference
<Thing>
Talk
<Place>
University
Ticket
WebSite
<Role>
Developer
JUG
<Description>
Category

26. Deep view
Booking
date
Enrollment
date
Payment
date
Invoice
date

27. <Place> website <Role> Developer <Thing> Talk
<Description>
Category
<Thing>
Talk
<Place>
Room
<Thing>
Ticket
<Event>
Enrollment
<Event>
Conference
<Event>
Presentation
<Event>
Survey
<Event>
Invoice
<Role>
JUG
<Role>
Expert
<Event>
Payment

28. view and models
more than you
need
unflexible
flexible

29. Summarizing models It´s your model , not the customer´s
Use,don’t show at first place
Time have no limits , be careful
Understand better your customer
Where does knowledge lie in the company ?

30. Agenda
Use
JPA
Problems
Create
Model

31. JPA and Domains
n+1
Queries
Lazy/
Eager
JoinFetch
Graphs

32. time to code

33. conclusions Use Analysis patterns in your models
Create a good model is hard
Is your responsibility
Know your framework

34. Thanks Cecilio Álvarez Caules contacto@arquitecturajava.com
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