Oracle ADF Interview Questions

1. What is Oracle ADF?

Answer: Oracle Application Development Framework (ADF) is a comprehensive Java EE framework for building enterprise applications. It provides a rich set of tools and components for rapid development, including data modeling, business logic, user interface, and integration with other systems.

2. What are the key components of Oracle ADF?

Answer:

• • ADF Business Components: For building and managing business logic, data access, and validation.
  • ADF Faces: A set of JSF-based UI components for creating rich user interfaces.
  • ADF Controller: For managing application flow and handling user interactions.
  • ADF Model: Connects the business logic layer with the presentation layer.
  • ADF Security: Provides comprehensive security features like authentication, authorization, and data encryption.

3. What are the benefits of using Oracle ADF?

Answer:

• • Rapid Development: Accelerates development with pre-built components and visual development tools.
  • Productivity: Increases developer productivity through code generation and visual editing.
  • Maintainability: Improves code maintainability with a modular architecture and clear separation of concerns.
  • Reusability: Encourages code reusability through the use of components and libraries.
  • Integration: Seamlessly integrates with other Oracle products and technologies.

4. Explain the difference between ADF BC and EJB.

Answer:

• • ADF BC: A framework specifically designed for Oracle ADF, offering features like declarative validation, automatic SQL generation, and optimized for ADF’s architecture.
  • EJB: A broader J2EE specification for enterprise Java beans, providing more general-purpose components like session beans, entity beans, and message-driven beans.

5. What is the role of the ADF Model layer?

Answer: The ADF Model layer acts as an intermediary between the business logic (ADF BC) and the presentation layer (ADF Faces). It provides a unified view of data and exposes it to the UI components.

6. What are the different types of ADF BC entities?

Answer:

• • View Object: Represents a query over one or more tables.
  • Entity Object: Represents a single row in a database table.
  • Application Module: A container for business services, providing transaction management and data caching.

7. How do you handle transactions in ADF BC?

Answer: Transactions are managed within the scope of an Application Module. You can define transaction boundaries using declarative rules or programmatically.

8. What are the different types of validators in ADF BC?

Answer:

• • Attribute Validators: Validate individual attributes of an entity.
  • Row Validators: Validate entire rows of data.
  • Entity Validators: Validate the entire entity object.

9. What are the different types of navigation rules in ADF?

• Answer:
  • Method Calls: Invoke methods on managed beans or other objects.
  • Page Flows: Define a sequence of pages to navigate through.
  • Task Flows: Reusable, self-contained units of work with their own flow definitions.

10. What is the purpose of Task Flows in ADF?

Answer: Task Flows promote code reusability by encapsulating a set of related activities, such as a wizard or a complex business process.

11. How do you handle security in ADF?

Answer: ADF provides features for:

• • Authentication: Verifying user identity.
  • Authorization: Controlling access to resources and operations.
  • Data Level Security: Restricting access to specific data based on user roles.

12. What are the different types of UI components in ADF Faces?

Answer:

• • Input Components: Text fields, checkboxes, radio buttons, etc.
  • Output Components: Labels, images, outputText, etc.
  • Data Visualization Components: Charts, tables, trees, etc.
  • Layout Components: Panels, forms, tables, etc.
  • Navigation Components: Buttons, links, command buttons, etc.

13. Explain the concept of binding in ADF Faces.

Answer: Binding allows you to connect UI components to data sources, such as ADF BC entities or managed beans, making it easier to display and manipulate data.

14. What is the purpose of the ADF Controller?

Answer: The ADF Controller manages the flow of an application, handles user events, and coordinates interactions between the Model and View layers.

15. What are the different types of bindings in ADF?

Answer:

• • Data Control Bindings: Bind UI components to data sources like ADF BC entities.
  • Method Bindings: Bind UI components to methods on managed beans or other objects.
  • Action Bindings: Bind UI components to actions that trigger navigation or other events.

16. How do you debug ADF applications?

Answer:

• • JDeveloper Debugger: Use the integrated debugger in JDeveloper to step through code, set breakpoints, and inspect variables.
  • Logging: Use the logging framework to trace application flow and identify issues.

17. What is the difference between View Objects and Entity Objects?

Answer:

• • View Object: Represents a query over one or more tables, providing a read-only or read-write view of the data.
  • Entity Object: Represents a single row in a database table, allowing for full CRUD (Create, Read, Update, Delete) operations.

18. What are transient attributes in ADF BC?

Answer: Transient attributes are attributes that are not persisted to the database. They are typically used for temporary storage or calculated values.

19. How do you implement search functionality in ADF?

Answer:

• • View Criteria: Create View Criteria to define search criteria and filter data in View Objects.
  • Search Forms: Create custom search forms using ADF Faces components to allow users to enter search criteria.

20. What is the purpose of the Data Control Palette in JDeveloper?

Answer: The Data Control Palette displays a hierarchical view of data sources (like ADF BC entities) and allows you to drag and drop components onto your JSF pages.

21. How do you internationalize an ADF application?

Answer:

• • ResourceBundle: Use ResourceBundles to store localized strings for different languages.
  • Locale: Set the user’s locale and use it to load the appropriate ResourceBundle.

22. What are the different types of validation in ADF BC?

Answer:

• • Mandatory: Ensures that a field is not empty.
  • Range: Checks if a value falls within a specified range.
  • Regular Expression: Validates a value against a regular expression pattern.
  • Custom Validators: Create custom validators for specific business rules.

23. How do you handle exceptions in ADF?

Answer:

• • Exception Handling: Use try-catch blocks to handle exceptions within your application code.
  • Error Handling: Display error messages to the user using ADF Faces components or JSF messages.

24. What are the different types of layouts in ADF Faces?

Answer:

• • Grid Layout: Arranges components in a grid of rows and columns.
  • Panel Layout: Groups components within a container.
  • Table Layout: Displays data in a tabular format.
  • Form Layout: Organizes input fields in a structured manner.

25. What are the advantages of using Task Flows over traditional page flows?

Answer:

• • Reusability: Task Flows can be reused across multiple applications or even within the same application.
  • Modularity: Encapsulate complex logic and improve code organization.
  • Testability: Easier to test and debug individual units of work.

26. What are the different types of Task Flows?

Answer:

• • Bounded Task Flows: Have a defined entry and exit point.
  • Unbounded Task Flows: Can be called multiple times and do not have a fixed exit point.

27. How do you pass parameters to a Task Flow?

Answer:

• • Parameters: Define input and output parameters for a Task Flow.
  • Bindings: Pass parameters using bindings between the caller and the called Task Flow.

28. What is the purpose of the ADF Model layer?

Answer: The ADF Model layer acts as an intermediary between the business logic (ADF BC) and the presentation layer (ADF Faces). It provides a unified view of data and exposes it to the UI components.

29. What are the different types of bindings in ADF?

Answer:

• • Data Control Bindings: Bind UI components to data sources like ADF BC entities.
  • Method Bindings: Bind UI components to methods on managed beans or other objects.
  • Action Bindings: Bind UI components to actions that trigger navigation or other event