DDD在旅游电商架构演进中的实践

1. DDD

2. CONTENTS 01 02 03 DDD

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4. BDD Layered architecture Layered Architecture Monoliths MicroKernel Hexagonal Architecture Modular monoliths Microkernel EDA X Onion Architecture Service-based architectures Screaming Architecture SOA MVC Microservices FP George Fairbanks Pattern-oriented Software Architecture

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6. VS VS D D D

7. VS - + … … + … … Software reuse is more like an organ transplant than snapping together Lego blocks. —John D. Cook

8. VS - <<inclu de>> <<inclu << < inc e> > n cl ude >> << inc lud e> lud de>> <<in cl <<in ude clud e>> >> <<in <<include>> clud e>> <<include>> > <<include>> in << d clu > e> ds> e> >> tends <<ex xten lud >> <<e << inc clude > <<include>> <<in

9. VS - … …

10. CONTENTS 01 02 03 DDD

11. + + • 购买 • 预约 • 零售 • 预订 • 团购 • 预售 • 代理 • 自营 • 拼团特产 • … • 分销 • 单品 • 搭售 • 预打死包 • 购物车 • 预打半活包 • … • 活包 • 门票 • 跟团 • 酒景 • 机酒 • 旅游用车 • 演出 • 特产 • …

12. - 1 - • • + • • •

13. - 1 - - cl u <<in > de> <<in <<inclu clud e>> de>> lud inc << <<include>> > e> <<inclu <<inclu de>> de>> <<include>> in << <> d clu > e> >> de c <<in > lude> <<inc <<in u ncl <> >> <<ex tends > > > de> cl <<in ude >>

14. 1 - - in cl << ud e> inc > lud e> > - lude << c <<in >> <<include>> <<includ <<in << inc lud << ex ten clud e>> e>> e> > … ds >> <<include>> << inc lud e> > … …

15. - 1 - e clud <<in - >> <<in <<include>> > <<include> <<include >> cl u d < e>> <<inclu de>> <<include>> lud inc <> > e> <<in <<include>> >> lude lud c <in <<include>> <<in clud c ten ex << <<include>> >> ds lud inc << > e> <<include>> <<in >> ds te n ex e>> << clud <<include>> > e> e>>

16. - 1 - - • • • • • • • • • • + • • • • • • •

17. - 1 - - 1 2 3 4 …

18. - 1 - - 1 1 * * * 1 1 1 * 1 1 1 * * 1 1 1 1 * * 1 * * 1 * 1 * * 1 1

19. - 1 - - • • + + • • • • • • • • • • • • • • • • • … • • • • • • •

20. - 1 1 - - 2 3

21. - 1 - • • Enforce linguistic boundaries to protect the validity of a domain term. + Linguistic boundaries are bounded context boundaries. • • 2PTS business capabilities are often strong indicators of linguistic boundaries • 2PTS from Millett S., Tune N. - Patterns, Principles, and Practices of Domain-Driven Design • from -

22. - 1 - - + + Product + +

23. - 1 - - Product Product Product Product

24. - 1 - - • • • • • • • • • • • • • • • • • • • … + + • • • • • • • • • • • …

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26. - 2 - • • • + • • -

27. e> ud cl in << ncl <> << > <<include>> << << in cl u de inc >> lud > e> ud cl in << << in cl ud e> e> > <<in clud e>> <> <<inclu ude > >> cl u d ncl e>> ude <<include lud <<in e> > - >> >> << inc 2 - <<include>> - << lu inc de >> <> <<include>> > << inc lud e>> > e> lud inc << <<include>> c in < < > de lu lude> > <<include>> << lud inc > e> <<include>> >> ude l c n <<i <<inc …

28. - 2 - <> <<inclu de>> << <<include>> << << inc lud inc lud e> > de <<inclu e> > n <> clud inc lud e> > e >> >> <<include >> > e> clu <<in de>> <<extends>> de>> <<ex tends > > lud inc << clu <<in de>> e>> > e> <<include >> <<inclu <<inclu lud << in << inc clu <<inclu de >> in << d clu de>> ude n cl < e> e>> in << d clu clud >> <<in <<include>> de>> <<include>> < cl e>

29. - 2 - - …

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31. - 2 - U D U D U D D D D D U U U D D U U U U U D D U D U D D D D U U D D U D U D U U

32. - - << in cl ud e> ude ncl < >> - <<in clud e>> <<include>> << << in … ❌ cl u de inc lud e> > >> … …

33. - 2 - - U D U D U D D D D D D U U U U D U U U U D D D U D D D U U D U U D D U D U U

34. - 2 - - D D U U U D D D D D D U U U U D U U U U D D D D D D U U D U D D D U D U U U U D U D D U U D U D D D U U U U

35. - 2 - • • • + • • • • • • • • • • • • • • • • • • • • • • • • • • 1 • … • … 2

36. CONTENTS 01 02 03 DDD

37. t x e t Con d e Architecture d n u o B e l u d o Probl M Domain em S pace service Solution Space m Mic u t n ro S a u Design Pattern ervi Q Compo ce tural nent c e t i library h Archite c r A ctural P attern Architectural Style

38. Application architecture Component Module Code Bounded Context Architectural Quantum library MicroService service — from Building evolutionary architecture Architectural Granularity Architectural Style Layered architecture monoliths Integration architecture Modular monoliths Service-based architectures Microservices

39. - Maintainability SRP LSP OCP Deployability CCP OO ADP Reusability Maintainability SDP REP DIP ISP Robert C. Martin Extensibility CRP Deployability SAP Agile Software Development, Principles, Patterns, and Practices, First Edition Package Principles Clean Architecture A Craftsman's Guide to Software Structure and Design Component Principles

40. Dr ivi ng Fo rc e - Gro u r m ain ten a ou Gr SRP p fo nce or p f CCP ADP reu s ser OCP LSP o Av OO SDP id REP un ne ed ed re le es ISP as DIP CRP SAP

41. - Eric Evans Robert C. Martin Policy Detail Communication Protocols DB IO Frameworks Messaging Transaction Persistence

42. - 1 Client - 2 3 Client Client Client User Interface Layer User Interface Layer Application Layer 4 Application Application Layer Application Layer Middle Layer DIP Third Party API Middle Layer Middle Layer Third Party API Third Party API Third Party API

43. - - 4 6 5 Client Client Client User Interface Layer User Interface Layer Application Layer DIP Application Layer Application Layer DIP Infrastructure Layer User Interface Layer DIP DIP DIP Infrastructure Layer Domain Layer DIP Infrastructure Layer Third Party API Third Party API Third Party API

44. - Client Client Client Adapter Adapter Application User Interface Layer +DIP Domain - Alistair Cockburn Adapter Third Party API Application Layer Adapter - Vaughn Vernon Third Party API es Domain Layer vic De Use Cases en ter es Pr DB ay ew t Ga Third Party API s Entities s External Interfaces UI Infrastructure Layer W eb Controllers - Robert C. Martin

45. - - Client Client Client Adapter Adapter Application User Interface Layer - Alistair Cockburn Adapter Application Layer - Vaughn Vernon - Eric Evans Third Party API Adapter Third Party API Policy - Robert C. Martin es Domain Layer vic en ter s External Interfaces UI DB ay ew t Ga Third Party API es Entities s Use Cases Pr Infrastructure Layer W eb Controllers De +DIP Domain - Robert C. Martin

46. - - Client SRP User Interface Layer Application Layer Domain Layer Infrastructure Layer Third Party API LSP OCP DIP Separation of Concerns: separate changes at different rates, for different reasons. The Axis of Change responsible for the creation of Architectural Boundaries. Build Software systems from interchangeable parts. Protect Policy from changes in Details Protect Client from changes in Domain Policy depend on Detail → Detail Depend on Policy

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