Overview: Adapters and Application Views

The Application View control allows WebLogic Workshop web services to access enterprise applications (also called Enterprise Information Systems or EISs). An EIS is typically a large-scale business application such as a Customer Relationship Management (CRM), Enterprise Resource Planning (ERP) or Human Resources (HR) application. Examples of EISs include SAP, PeopleSoft or Siebel.

# Adapters

In order to integrate the operations of an enterprise, the data and functions of the various EISs in an organization must be exposed. In the Java 2 Enterprise Edition (J2EE) model, EIS functionality is exposed to Java clients using an adapter (sometimes called a resource adapter or a connector) according to the J2EE Connector Architecture. Adapters for popular EISs are available from the applications' vendors, from BEA Systems and from third-party vendors.

WebLogic Integration (WLI), the enterprise integration offering BEA Systems, includes, as part of its Application Integration (AI) component, the Adapter Development Kit (ADK). A developer can use the ADK to construct adapters, which define services and events.

A service represents a message that requests a specific action in the EIS. For example, an adapter might define a service named AddCustomer that accepts a message defining a customer and then invokes the EIS to create the appropriate customer record.

An event issues messages when events of interest occur in the EIS. For example, an adapter might define an event that sends messages to interested parties whenever any customer record is updated in the EIS.

# Application Views

In addition to defining and implementing adapters, the AI component of WebLogic Integration enables a developer to create Application Views. An Application View provides a layer of abstraction on top of an adapter; whereas adapters are closely associated with the specific functions available in the EIS, an application view is associated with business processes that must be accomplished by clients. The Application View converts the steps in the business process into operations on the adapter.

An application view exposes services and events that serve the business process. The WebLogic Workshop Application View control is associated with a particular Application View, and makes the services and methods of the Application View available to WebLogic Workshop web services as control methods and callbacks.