1. JDeveloper 10g and Oracle ADF Business Components Getting the Most Out of Your Data Avrom Roy-Faderman Senior Programmer November, 2005

2. Agenda J2EE, ADF, and JDeveloper Why Business Components? Reading Data Changing Data Transactions Demo Q&A

3. What Is J2EE? Java platform for multi-tier applications Open Scalable Traditionally difficult to use 3GL Much time spent on application plumbing

4. Frameworks Library of classes Handle plumbing automatically XML files provide customization Can make Java more like a 4GL

5. ADF and MVC Business Services View (Web and Wireless Clients) View and Controller (Desktop Clients) Model Controller (Web and Wireless Clients) Oracle ADF is a framework based on MVC architecture

6. ADF and MVC ADF Business Components ADF UIXADF Swing ADF Data Bindings Struts + ADF Extensions Oracle ADF is a framework based on MVC architecture

7. Agenda J2EE, ADF, and JDeveloper Why Business Components? Reading Data Changing Data Transactions Demo Q&A

8. Impedence Mismatch SQL Tables, rows Primary keys Foreign keys Transactions GB, TB Java Classes, instances Memory references Object members Shared heap 100s of MB

9. ADF BC Bridges the Gap SQL Tables, rows Primary keys Foreign keys Transactions GB, TB Java Classes, instances Memory references Object members Shared heap 100s of MB

10. ADF BC Functionality Reading data Caching data Writing data Managing relationships Managing transactions

11. What they Don’t Do Create user interface (view) Organize the flow of the application (controller)

12. Agenda J2EE, ADF, and JDeveloper Why Business Components? Reading Data Changing Data Transactions Demo Q&A

13. Reading Data ADF View Objects ADF View Links

14. ADF View Objects Retrieve data from the database Manage caches of data “View object definitions” contain SQL queries and act as templates for “view object instances”

15. ADF View Objects Each view object instance can execute the SQL query and cache the results Database View object instance Data Data rows Data View rows SQL query Data retrieval

16. View Object Attributes Every query column maps to a view object attribute Those attributes are visible to the application SELECT E.EMPLOYEE_ID, E.LAST_NAME, D.DEPARTMENT_ID, D.DEPARTMENT_NAME FROM EMPLOYEES E, DEPARTMENTS D WHERE E.DEPARTMENT_ID = D.DEPARTMENT_ID EmployeeId LastName DepartmentId DepartmentName

17. View Objects Don’t Write! Classes to do DML are too heavyweight if not needed Some query columns hard to map backwards

18. Reading Data ADF View Objects ADF View Links

19. “View link definitions” relate a pair of view object definitions View link definitions specify master/detail relationships between the SQL queries

20. ADF View Links View link definitions have “Source” and “Destination” attributes These attributes specify the master-detail relationship Just like foreign key and primary key attributes specify a foreign key relationship

21. ADF View Links A view link definition works like an additional WHERE clause applied to the detail SELECT E.EMPLOYEE_ID, E.LAST_NAME FROM EMPLOYEES E EmployeesView (Master) SELECT D.DEPARTMENT_ID, D.DEPARTMENT_NAME, D.MANAGER_ID FROM DEPARTMENTS D DepartmentsView (Detail) WHERE D.MANAGER_ID = :1 Source attribute Destination attribute

22. Agenda J2EE, ADF, and JDeveloper Why Business Components? Reading Data Changing Data Transactions Demo Q&A

23. Changing Data ADF Entity Objects View and Entity Attributes

24. ADF Entity Objects “Entity object definitions” correspond to database tables. Entity object definitions are templates for “entity object instances,” which correspond to table rows.

25. View Objects and Entity Objects Instead of caching data themselves, view object instances can store data in entity object instances Database View object instance Data Data rows Data View rows SQL query Data Entity object instances Data retrieval

26. View Objects and Entity Objects The entity object instances can write back to the database Entity object definitions can specify validation rules Database View object instance Data Data rows Data View rows Data Entity object instances DML

27. Entity Object Attributes Every table column maps to an entity object attribute EmployeeId FirstName LastName Salary … EMPLOYEE_IDFIRST_NAMELAST_NAMESALARY...

28. Changing Data ADF Entity Objects View and Entity Attributes

29. Every view object attribute can map to an entity attribute EmployeeId FirstName LastName DepartmentId … EmployeeId LastName DepartmentId DepartmentName

30. One View, Many Entities One view object definition can map to multiple entity object definitions EmployeeId FirstName LastName DepartmentId … EmployeeId LastName DepartmentId DepartmentName DepartmentId DepartmentName ManagerId LocationId … Employees Departments EmpDeptView

31. One View, Many Entities Then each view row will map to multiple entity object instances Data View rows Data Entity object instances Data Entity object instances Employees Departments

32. One Entity, Many Views Multiple view object definitions can map to a single entity object definition EmployeeId LastName DepartmentId DepartmentName DepartmentId DepartmentName ManagerId LocationId … EmpDeptView DepartmentId DepartmentName LocationId LocationName DeptLocView

33. One Entity, Many Views Then different view object instances can share data Data View rows Data Entity object instances EmpDeptView instance Data View rows DeptLocView instance

34. SQL-Only View Attributes View attributes don’t need to map to entity attributes at all Then they must be read-only E.g.: Caclulated query columns

35. Read-Only View Objects Have only SQL-Only attributes Do not use entity objects at all Read-only access to data But

36. Agenda J2EE, ADF, and JDeveloper Why Business Components? Reading Data Changing Data Transactions Demo Q&A

37. Application Modules Application modules package up the data and present it to the rest of the application The application always talks to the business components through the application module

38. Application Module Instances Each instance (user) of the application will get its own application module instance The application module instance contains view object instances View object instances use entity object instances to write

39. The Data Model The view object instances in an application module instance are joined in master-detail relationships by “view link instances” The resulting tree is called the “data model”

40. A Simple Data Model Instance of EmployeesView Instance of DepartmentsView Instance of DeptMgrLink SELECT E.EMPLOYEE_ID, E.LAST_NAME FROM EMPLOYEES E SELECT D.DEPARTMENT_ID, D.DEPARTMENT_NAME, D.MANAGER_ID FROM DEPARTMENTS D WHERE D.MANAGER_ID = :current_employee_id

41. A More Complex Data Model Master Instance of EmployeesView Detail Instance of DepartmentsView Detail Instance of EmployeesView Independent Instance of DepartmentsView

42. Application Module Definitions Templates for application module instances Specify which view object and view link instances should go in the data model

43. Data Consistency Each application module instance has its own set of view and entity caches Two locking mode choices “Pessimistic” locks (the default) acquired on DB rows as soon as data is changed in the cache “Optimistic” locks acquired just before executing DML

44. Demo

45. Q & A