1.1 Introduction to Oracle ADF
The Oracle Application Development Framework (Oracle ADF) is an end-to-end application framework that builds on Java Platform, Enterprise Edition (Java EE) standards and open-source technologies. You can use Oracle ADF to implement enterprise solutions that search, display, create, modify, and validate data using web, wireless, desktop, or web services interfaces. Because of its declarative nature, Oracle ADF simplifies and accelerates development by allowing users to focus on the logic of application creation rather than coding details. Used in tandem, Oracle JDeveloper 11g and Oracle ADF give you an environment that covers the full development lifecycle from design to deployment, with drag-and-drop data binding, visual UI design, and team development features built in.
You can download and view the Fusion Order demo application, which helps to illustrate the concepts and procedures in this guide (and other Fusion Middleware developer guides). The StoreFront module of this application is built using the Fusion web application technology stack, which includes ADF Business Components, ADF Model, ADF Controller, and JavaServer Faces pages with ADF Faces rich client components. Screenshots and code samples from this module are used throughout this guide to provide you with real-world examples of using the Oracle ADF technologies in an application that uses the Fusion web technology stack. For more information about downloading and using the StoreFront module of the Fusion Order Demo application, see Chapter 2, "Introduction to the ADF Sample Application."
1.2 Oracle ADF Architecture
In line with community best practices, applications you build using the Fusion web technology stack achieve a clean separation of business logic, page navigation, and user interface by adhering to a model-view-controller architecture. As shown in Figure 1-1, in an MVC architecture:
The model layer represents the data values related to the current page
The view layer contains the UI pages used to view or modify that data
The controller layer processes user input and determines page navigation
The business service layer handles data access and encapsulates business logic
illustrates where each ADF module fits in the Fusion web application architecture. The core module in the framework is ADF Model, a data binding facility. The ADF Model layer enables a unified approach to bind any user interface to any business service, without the need to write code. The other modules that make up a Fusion web application technology stack are:
ADF Business Components, which simplifies building business services.
ADF Faces rich client, which offers a rich library of AJAX-enabled UI components for web applications built with JavaServer Faces (JSF).
ADF Controller, which integrates JSF with ADF Model. The ADF Controller extends the standard JSF controller by providing additional functionality, such as reusable task flows that pass control not only between JSF pages, but also between other activities, for instance method calls or other task flows.
Note:
In addition to ADF Faces, Oracle ADF also supports using the Swing, JSP, and standard JSF view technologies. For more information about these technologies, refer to the JDeveloper online help. Oracle ADF also provides support for using Microsoft Excel as a view layer for your application. For more information, see the Oracle Fusion Middleware Desktop Integration Developer's Guide for Oracle Application Development Framework
Figure 1-2 Simple Oracle ADF Architecture
Image of ADF architecture
1.2.1 ADF Business Components
When building service-oriented Java EE applications, you implement your core business logic as one or more business services. These backend services provide clients with a way to query, insert, update, and delete business data as required while enforcing appropriate business rules. ADF Business Components are prebuilt application objects that accelerate the job of delivering and maintaining high-performance, richly functional, database-centric services. They provide you with a ready-to-use implementation of Java EE design patterns and best practices.
As illustrated in Figure 1-3, Oracle ADF provides the following key components to simplify building database-centric business services:
Entity object
An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. It can encapsulate business logic to ensure that your business rules are consistently enforced. You associate an entity object with others to reflect relationships in the underlying database schema to create a layer of business domain objects to reuse in multiple applications.
View object
A view object represents a SQL query and simplifies working with its results. You use the SQL language to join, filter, sort, and aggregate data into the shape required by the end-user task being represented in the user interface. This includes the ability to link a view object with other entity objects to create master-detail hierarchies of any complexity. When end users modify data in the user interface, your view objects collaborate with entity objects to consistently validate and save the changes.
Application module
An application module is the transactional component that UI clients use to work with application data. It defines an updateable data model along with top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task.
Figure 1-3 ADF Business Components Simplify Data Access and Validation
Image of data access, validation in ADF business components
Tip:
If you have previously worked with Oracle Forms, note that this combined functionality is the same set of data-centric features provided by the form, data blocks, record manager, and form-level procedures or functions. The key difference in Oracle ADF is that the user interface is cleanly separated from data access and validation functionality. For more information, see Appendix G, "Performing Common Oracle Forms Tasks in Oracle ADF."
1.2.2 ADF Model Layer
The ADF Model layer abstracts the business service implementation, providing a single programming interface for different types of services. Data controls provide this interface by using standard metadata interfaces to describe the service's operations and data collections, including information about the properties, methods, and types involved. In JDeveloper, the functionality and attributes exposed by a business service are indicated by icons in the Data Controls panel. You can drag and drop onto a page to create UI components. JDeveloper automatically creates the bindings from the page and the UI components to the services. At runtime, the ADF Model layer reads the information describing your data controls and data bindings from appropriate XML files and implements the two-way connection between your user interface and your business service.
Oracle ADF provides out-of-the-box data control implementations for the most common business service technologies. Using JDeveloper and Oracle ADF together provides you with a drag-and-drop data binding experience as you build your user interfaces. Along with support for ADF application modules, ADF Model also provides support for the following service technologies:
Enterprise JavaBeans (EJB) session beans and JPA entities
JavaBeans
Web services
XML
CSV files
1.2.3 ADF Controller
In the controller layer, where handling page flow of your web applications is a key concern, ADF Controller provides an enhanced navigation and state management model on top of JSF. JDeveloper allows you to declaratively create task flows where you can pass application control between different types of activities, such as pages, methods on managed beans, case statements, or calls to other task flows.
These task flows can be reused, and can also be nested, both within themselves and within pages. Task flows nested in pages become regions that contain their own set of navigatable pages, allowing users to view a number of different pages and functionality without leaving the main page.
The Oracle Application Development Framework (Oracle ADF) is an end-to-end application framework that builds on Java Platform, Enterprise Edition (Java EE) standards and open-source technologies. You can use Oracle ADF to implement enterprise solutions that search, display, create, modify, and validate data using web, wireless, desktop, or web services interfaces. Because of its declarative nature, Oracle ADF simplifies and accelerates development by allowing users to focus on the logic of application creation rather than coding details. Used in tandem, Oracle JDeveloper 11g and Oracle ADF give you an environment that covers the full development lifecycle from design to deployment, with drag-and-drop data binding, visual UI design, and team development features built in.
You can download and view the Fusion Order demo application, which helps to illustrate the concepts and procedures in this guide (and other Fusion Middleware developer guides). The StoreFront module of this application is built using the Fusion web application technology stack, which includes ADF Business Components, ADF Model, ADF Controller, and JavaServer Faces pages with ADF Faces rich client components. Screenshots and code samples from this module are used throughout this guide to provide you with real-world examples of using the Oracle ADF technologies in an application that uses the Fusion web technology stack. For more information about downloading and using the StoreFront module of the Fusion Order Demo application, see Chapter 2, "Introduction to the ADF Sample Application."
1.2 Oracle ADF Architecture
In line with community best practices, applications you build using the Fusion web technology stack achieve a clean separation of business logic, page navigation, and user interface by adhering to a model-view-controller architecture. As shown in Figure 1-1, in an MVC architecture:
The model layer represents the data values related to the current page
The view layer contains the UI pages used to view or modify that data
The controller layer processes user input and determines page navigation
The business service layer handles data access and encapsulates business logic
illustrates where each ADF module fits in the Fusion web application architecture. The core module in the framework is ADF Model, a data binding facility. The ADF Model layer enables a unified approach to bind any user interface to any business service, without the need to write code. The other modules that make up a Fusion web application technology stack are:
ADF Business Components, which simplifies building business services.
ADF Faces rich client, which offers a rich library of AJAX-enabled UI components for web applications built with JavaServer Faces (JSF).
ADF Controller, which integrates JSF with ADF Model. The ADF Controller extends the standard JSF controller by providing additional functionality, such as reusable task flows that pass control not only between JSF pages, but also between other activities, for instance method calls or other task flows.
Note:
In addition to ADF Faces, Oracle ADF also supports using the Swing, JSP, and standard JSF view technologies. For more information about these technologies, refer to the JDeveloper online help. Oracle ADF also provides support for using Microsoft Excel as a view layer for your application. For more information, see the Oracle Fusion Middleware Desktop Integration Developer's Guide for Oracle Application Development Framework
Figure 1-2 Simple Oracle ADF Architecture
Image of ADF architecture
1.2.1 ADF Business Components
When building service-oriented Java EE applications, you implement your core business logic as one or more business services. These backend services provide clients with a way to query, insert, update, and delete business data as required while enforcing appropriate business rules. ADF Business Components are prebuilt application objects that accelerate the job of delivering and maintaining high-performance, richly functional, database-centric services. They provide you with a ready-to-use implementation of Java EE design patterns and best practices.
As illustrated in Figure 1-3, Oracle ADF provides the following key components to simplify building database-centric business services:
Entity object
An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. It can encapsulate business logic to ensure that your business rules are consistently enforced. You associate an entity object with others to reflect relationships in the underlying database schema to create a layer of business domain objects to reuse in multiple applications.
View object
A view object represents a SQL query and simplifies working with its results. You use the SQL language to join, filter, sort, and aggregate data into the shape required by the end-user task being represented in the user interface. This includes the ability to link a view object with other entity objects to create master-detail hierarchies of any complexity. When end users modify data in the user interface, your view objects collaborate with entity objects to consistently validate and save the changes.
Application module
An application module is the transactional component that UI clients use to work with application data. It defines an updateable data model along with top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task.
Figure 1-3 ADF Business Components Simplify Data Access and Validation
Image of data access, validation in ADF business components
Tip:
If you have previously worked with Oracle Forms, note that this combined functionality is the same set of data-centric features provided by the form, data blocks, record manager, and form-level procedures or functions. The key difference in Oracle ADF is that the user interface is cleanly separated from data access and validation functionality. For more information, see Appendix G, "Performing Common Oracle Forms Tasks in Oracle ADF."
1.2.2 ADF Model Layer
The ADF Model layer abstracts the business service implementation, providing a single programming interface for different types of services. Data controls provide this interface by using standard metadata interfaces to describe the service's operations and data collections, including information about the properties, methods, and types involved. In JDeveloper, the functionality and attributes exposed by a business service are indicated by icons in the Data Controls panel. You can drag and drop onto a page to create UI components. JDeveloper automatically creates the bindings from the page and the UI components to the services. At runtime, the ADF Model layer reads the information describing your data controls and data bindings from appropriate XML files and implements the two-way connection between your user interface and your business service.
Oracle ADF provides out-of-the-box data control implementations for the most common business service technologies. Using JDeveloper and Oracle ADF together provides you with a drag-and-drop data binding experience as you build your user interfaces. Along with support for ADF application modules, ADF Model also provides support for the following service technologies:
Enterprise JavaBeans (EJB) session beans and JPA entities
JavaBeans
Web services
XML
CSV files
1.2.3 ADF Controller
In the controller layer, where handling page flow of your web applications is a key concern, ADF Controller provides an enhanced navigation and state management model on top of JSF. JDeveloper allows you to declaratively create task flows where you can pass application control between different types of activities, such as pages, methods on managed beans, case statements, or calls to other task flows.
These task flows can be reused, and can also be nested, both within themselves and within pages. Task flows nested in pages become regions that contain their own set of navigatable pages, allowing users to view a number of different pages and functionality without leaving the main page.
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