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Introduction to Using Application Integration
Welcome to the BEA WebLogic Application Integration User Guide, the guide for using adapters built using the BEA Application Integration ADK (Adapter Development Kit). This document explains how to define application view services and events and use them in your business processes.
The instructions in this document are general instructions. Because each adapter and application is different, the instructions do not cover any information specific to any particular adapter or application. If you are looking for a tour of specific adapters developed using Application Integration ADK, see the following two sections in "BEA WebLogic Application Integration Development Guide:"
This section provides information on the following subjects:
Before You Begin
Before you can begin using adapters to integrate your enterprise, make sure the following prerequisites are satisfied:
Note: For a complete list of prerequisites, see BEA WebLogic Application Integration Release Notes.
Concepts
This section describes important concepts with which you should familiarize yourself before you use Application Integration. The following concepts are discussed in detail in Defining Application Views and Using Application Views in WebLogic Process Integrator. For a broad overview of BEA WebLogic Application Integration, see the BEA WebLogic Integration Framework Getting Started Guide.
Adapters: XML Interfaces to an EIS
In Application Integration, an adapter is software that forms an XML-based interface for connecting an Enterprise Information Server (EIS) and your enterprise's WebLogic server. An adapter enables application-level communication between the WebLogic server and a particular EIS in your enterprise. In your organization, you probably have a variety of separate EIS systems whose applications must interact with each another. In the Application Integration environment, you don't have to connect each EIS to every other EIS in your enterprise. Instead, you develop an adapter for each EIS.
Application Views
The application view is the cornerstone of BEA WebLogic Application Integration's Integration Framework. It provides a view of the application capabilities exposed by an adapter that a user can customize to meet specific business needs. A user tailors an application view for a specific business purpose, and as a result, the application view provides an effective alternative to the "one size fits all" approach that most applications provide for the design of their client interface. The application view allows you to define for it only the business capabilities that directly apply to your business purpose. You can customize the capabilities by naming, describing and defining their data requirements. For more information about application views, see BEA WebLogic Application Integration Adapter Development Guide
An application view has the following basic properties:
An application view's communication parameters provide the "rules of the road" used by the WebLogic server and the EIS application to communicate and perform housekeeping. An application view is a business-level interface that uses the capabilities of the EIS, via the adapter, to implement the business function of a service and to deliver events of significance to the business. You can add any number of services and events to each application view. For more information about events and services, see BEA WebLogic Application Integration Adapter Development Guide. For more information on defining application views, see Introduction to Defining Application Views.
When to use Application Views and
When to Write Custom Code
To support service invocation and events, you can define application views, or you can write custom code that accomplishes the same functions. Application views provide the most convenient interface to an adapter's resources, but there are other ways to access an adapter. Normally, for each WebLogic adapter, you will define application views to expose the application functions. However, for those who require more control, you may also write custom code to access the resources of an adapter. For your enterprise, you must decide whether to define application views or write your own code.
When to Define Application Views
You can define application views to easily integrate most EIS applications. In general, define application views in the following situations:
When to Write Custom Code Instead of
Defining Application Views
In general, write custom code as an interface to an adapter only in the following situations:
"Defining" Versus "Using" Application Views
There are two initial steps in the life cycle of an application view:
Defining: Configuring the Application View
and Adding Events and Services
When you define an application view, you configure the communication parameters, then add services and/or events. For more information about services and events, see BEA WebLogic Application Integration Adapter Development Guide. Defining an application view includes the following tasks:
Using Application Views in Business Processes
After you define an application view, you can deploy it on the Application Integration server. You can use deployed application views to implement your enterprise's business processes.
After using an application view in a business process, the end result is a deployed electronic representation of your enterprise's business process. The business process specifies how your enterprise's EIS will interact with each other to accomplish the business processes. The application views perform the business functions designated by the business process and deliver events from the EIS to drive a business process.
Services and Events
For each application view, you can add any number of services and events, which support specific types of interactions/communiccation between the WebLogic server and the target EIS application. Services and events provide an XML-based interface between the WebLogic server and the functions of the target EIS.
Understanding Services
Services act as business functions that may be invoked by a user. Service invocations cause messages to be sent to an application following the request/response model.For each application view, you can define any number of services. Services are self-describing software modules that expose a simple XML-based request/response interface.
An application view's services receive a particular type of XML document from the client and then perform a specified function on a designated EIS application. When the EIS application receives the message from the service, it may or may not send back a response to the service. Each service represents a particular transaction the EIS application can perform, and the application view manages the mapping of its services to EIS functions.
Synchronous and Asynchronous Services
Any service may be invoked either synchronously or asynchronously. The method of invocation you choose depends on the technical implementation in which the application view is being used.
Understanding Events
Events enable messages generated by an application to be managed following a publish/subscribe model. For each application view, you can designate any number of events. An application view event represents a change in the state of an EIS, extracts data about the event from the EIS, then propagates the data into the WebLogic environment.
Using the Application View Management Console
You can organize all of your application views into folders so you can look them up using your own organizational scheme. Once you set up a folder tree, you can browse all application views in your enterprise without regard to the adapter used to define the application view. You can use the Application View Management Console to create new folders and to define new application views in them. For details, see Using the Application View Management Console.
Who Uses Adapters and Application Views?
In your enterprise, several people may share the responsibilities of maintaining WebLogic adapters, application views, and their services and events. In most enterprises, these people can be grouped into one of three categories:
System Administrator
System administrators are responsible for installing the BEA WebLogic Application Integration ADK.
Adapter Developers
If you are a software developer or a high-level technician in your enterprise, you are probably an adapter developer. Adapter developers commonly use the ADK to develop new adapters for EIS systems and design the accompanying user interface that the adapter user will interact with when creating application views using the adapter. For information on developing adapters, see the BEA WebLogic Application Integration Adapter Development Guide.
Adapter Users
If you are a business analyst, EIS specialist, or technical analyst in your enterprise, you are probably an adapter user. Adapter users do not usually develop adapters but may provide specifications to the adapter developer. Once an adapter is developed, adapter users normally define and manage application views that use it.
How Responsibilities are Distributed Among Users
Table 1-1 shows how tasks and responsibilities are typically divided.
Table 1-1 Common Jobs and Their Owners
Defining Application Views When you define an application view using an adapter, you are creating an XML-based interface between WebLogic and a particular EIS application. For detailed steps for defining application views using adapters, see Defining Application Views. Defining an application view involves these basic steps:
Creating an Application View
The first step in creating an application view based on an adapter is to log on to the Application View Administration Console, choose a folder where the application view will reside, and configure its communication parameters. For details on creating and configuring an application view, see the following topics:
Adding Services and Events to an Application View
After defining the communication parameters of the application view, the next step is to add services and events. Services and events support a subset of an application's business processes by allowing other WebLogic entities to interact with the application functions you specify. The application view services and events allow specific types of transactions between the WebLogic server and the EIS application. For details on adding services and events to an application view, see the following topics:
Testing Services and Events
After adding a service or event to an application view, you must make sure the service or event interacts properly with the EIS application. For details on testing services and events, see the following topics:
Using Application Views in Business Processes
Once you define an application view in your WebLogic environment, you can use the application view in your enterprise's business processes. There are two ways to use application views in business processes:
Using Application Views in WebLogic Process Integrator
The most common way to use an application view in your enterprise's business processes is to design a workflow in WebLogic Process Integrator. Process Integrator provides a GUI-based environment for designing business process workflows. These workflows can include application view services and events defined using Application Integration.
There are four ways to use an application view in a workflow using WebLogic Process Integrator:
For detailed information on each method, see Using Application Views in WebLogic Process Integrator.
Using Application Views by Writing Custom Code
If you do not use WebLogic Process Integrator, the alternate way to use an application view in your enterprise is to write custom Java code to implement a business process.
For detailed steps for custom coding business processes, see Using Application Views by Writing Custom Code.
Deciding Which of the Two Methods to Use
For each business process you implement, you will need to decide which of the two implementation methods to use. You can implement any business processes as a workflow using WebLogic Process Integrator. In this document, custom coding is offered only as an alternate method for those who require it.
When to Use WebLogic Process Integrator
In general, use WebLogic Process Integrator to implement a business process in the following situations:
For example, if a business process receives events, selects only a subset of the events, performs complex branched actions, then generates many complex messages and sends the messages to a variety of WebLogic clients, then you should use WebLogic Process Integrator to implement the business process.
When to Write Custom Java Code
In general, write custom code to implement a business process only in the following situations:
For example, if a business process performs a limited set of actions on an incoming message, then routes the minimally transformed message to a small number of client applications, then the business process is simple enough to express by writing custom code.
When you update custom code, the change requires a full compile/test/debug cycle, which can be costly.
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