1. COMP9321 Web Application Engineering Semester 2, 2016
Dr. Amin Beheshti
Service Oriented Computing Group, CSE, UNSW Australia
Week 7
COMP9321, 16s2, Week 7

2. Design Patterns
A pattern is a proven solution to a problem in a context.
COMP9321, 16s2, Week 7

3. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
COMP9321, 16s2, Week 7

4. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
A design pattern represents a solutions to problems that arise when developing a software.
COMP9321, 16s2, Week 7

5. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
A design pattern represents a solutions to problems that arise when developing a software.
Frameworks
Subsystems
Sub-subsystems
Design pattern are granular and applied at different levels such as:
COMP9321, 16s2, Week 7

6. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
A design pattern represents a solutions to problems that arise when developing a software.
Frameworks
Subsystems
Sub-subsystems
Design pattern are granular and applied at different levels such as:
Design
Architectural
Analysis
Creational
Structural
Behavioral
Categories include:
COMP9321, 16s2, Week 7

7. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
A design pattern represents a solutions to problems that arise when developing a software.
Frameworks
Subsystems
Sub-subsystems
Design pattern are granular and applied at different levels such as:
Design
Architectural
Analysis
Creational
Structural
Behavioral
e.g.
MVC: Model View Controller
Categories include:
COMP9321, 16s2, Week 7

8. Design Patterns
A pattern is a proven solution to a problem in a context.
Each pattern expresses a relation between a certain context, a problem, and a solution.
A design pattern represents a solutions to problems that arise when developing a software.
Frameworks
Subsystems
Sub-subsystems
Design pattern are granular and applied at different levels such as:
Design
Architectural
Analysis
Creational
Structural
Behavioral
Categories include:
Gamma et al (Gang of Four) produced a famous book which listed 23 “Design” patterns
COMP9321, 16s2, Week 7

9. J2EE Design Patterns
COMP9321, 16s2, Week 7

10. J2EE Design Patterns
COMP9321, 16s2, Week 7

11. Web Application Architecture
COMP9321, 16s2, Week 7

12. Web Application Architecture
COMP9321, 16s2, Week 7

13. Web Application Architecture
COMP9321, 16s2, Week 7

14. Web Application Architecture
COMP9321, 16s2, Week 7

15. Web Application Architecture
COMP9321, 16s2, Week 7

16. Web Application Layers
COMP9321, 16s2, Week 7

17. J2EE design guidelines: Web tier
COMP9321, 16s2, Week 7

18. J2EE design guidelines: Web tier
COMP9321, 16s2, Week 7

19. Servlet Design Guidelines
COMP9321, 16s2, Week 7

20. Servlet design guidelines: When to use Servlets
COMP9321, 16s2, Week 7

21. Servlet design guidelines: When to use Servlets
COMP9321, 16s2, Week 7

22. JSP Design Guidelines
COMP9321, 16s2, Week 7

23. JSP Design Guidelines
COMP9321, 16s2, Week 7

24. JSP Design Guidelines
COMP9321, 16s2, Week 7

25. JSP Design Guidelines
Include directive includes the file at translation time;
whereas the include action includes the file at runtime.
COMP9321, 16s2, Week 7

26. JSP Design Guidelines
COMP9321, 16s2, Week 7

27. JSP Design Guidelines
COMP9321, 16s2, Week 7

28. JSP Design Guidelines
COMP9321, 16s2, Week 7

29. General Guideline for Servlet/JSP/JavaBeans
COMP9321, 16s2, Week 7

30. General Guideline for Servlet/JSP/JavaBeans
COMP9321, 16s2, Week 7

31. General Guideline for Servlet/JSP/JavaBeans
COMP9321, 16s2, Week 7

32. Structuring Web applications Architectural Patterns (MVC)
COMP9321, 16s2, Week 7

33. Structuring Web applications
COMP9321, 16s2, Week 7

34. Structuring Web applications
COMP9321, 16s2, Week 7

35. Structuring Web applications
COMP9321, 16s2, Week 7

36. Model 1 Example
COMP9321, 16s2, Week 7

37. Model 1 Example
COMP9321, 16s2, Week 7

38. Model 1 Example
COMP9321, 16s2, Week 7

39. Model 1 Example
COMP9321, 16s2, Week 7

40. Model 1 Example
COMP9321, 16s2, Week 7

41. Model 1 Example
COMP9321, 16s2, Week 7

42. Model 1 Architecture
COMP9321, 16s2, Week 7

43. MVC Model View Controller
COMP9321, 16s2, Week 7

44. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

45. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

46. MVC Components and Roles
MVC can be broken down into three elements:
Model - The model represents data and the rules that govern access to and updates of this data.
View - The view renders the contents of a model. It specifies exactly how the model data should be presented.
Controller - The controller translates the user's interactions with the view into actions that the model will perform.
COMP9321, 16s2, Week 7

47. MVC Components and Roles
COMP9321, 16s2, Week 7

48. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

49. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

50. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

51. Model 2 Architecture = MVC pattern
COMP9321, 16s2, Week 7

52. Case for a centralised controller
COMP9321, 16s2, Week 7

53. Case for a centralised controller
COMP9321, 16s2, Week 7

54. Case for multiple controllers
COMP9321, 16s2, Week 7

55. FrontController Pattern
COMP9321, 16s2, Week 7

56. FrontController Pattern
The Front Controller pattern is a software design pattern.
The pattern relates to the design of web applications.
It provides a centralized entry point for handling requests.
Front controllers are often used in web applications to implement workflows.
The front controller may be implemented as a Java object.
COMP9321, 16s2, Week 7

57. FrontController Pattern
The Front Controller pattern is a software design pattern.
The pattern relates to the design of web applications.
It provides a centralized entry point for handling requests.
Front controllers are often used in web applications to implement workflows.
The front controller may be implemented as a Java object.
COMP9321, 16s2, Week 7

58. FrontController implementation: Command Design Pattern
COMP9321, 16s2, Week 7

59. Command Design Pattern
COMP9321, 16s2, Week 7

60. Command Design Pattern
COMP9321, 16s2, Week 7

61. Command Design Pattern
COMP9321, 16s2, Week 7

62. Command Design Pattern
COMP9321, 16s2, Week 7

63. Command Design Pattern
COMP9321, 16s2, Week 7

64. Command Design Pattern
COMP9321, 16s2, Week 7

65. Command Design Pattern
COMP9321, 16s2, Week 7

66. Command Design Pattern
COMP9321, 16s2, Week 7

67. Command Design Pattern
COMP9321, 16s2, Week 7

68. Command Design Pattern
COMP9321, 16s2, Week 7

69. Command Design Pattern
COMP9321, 16s2, Week 7

70. Identifying the Command Pattern in the phonebook lab
COMP9321, 16s2, Week 7

71. Implementing the Command Pattern
COMP9321, 16s2, Week 7

72. Typical "Assignment 2" Architecture
COMP9321, 16s2, Week 7

73. Next Week
COMP9321, 16s2, Week 7

74. References
Core J2EE patterns, Deepak Alur, John Crupi and Dan Marlks, Prentice Hall
Patterns of Enterprise Application Architecture, Martin Fowler, Addison-Wesley
COMP9321, 16s2, Week 7

75. COMP9321, 16s2, Week 7