Managing Information Access to an Enterprise Information System Using J2EE and Services Oriented Architecture

Chapter 8. Integration using WebSphere Business Integration Adapters 201

򐂰 Bi-directional

The adapters have the ability to both send information to the EIS and to

retrieve events from the EIS. The process of sending information to the EIS is

referred to as

request processing. Processing a request from an integration

broker or a client service to perform an operation in the EIS.

Event

notification

is the retrieval of changes and updates in an EIS component and

propagating these changes to an integration broker or client service.

򐂰 Multi-threaded request processing

Typically, an adapter is multi-threaded during request processing. Thus, the

adapter can handle multiple simultaneous requests to perform different

operations on the EIS, allowing for scalability and better performance.

There are two distinct type of adapters:

򐂰 Application adapters

򐂰 Technology adapters

These two types of adapters allow integration with legacy applications,

mainframe systems, and different technologies. The application adapters provide

for integration through the use of the EIS-specific API. These EIS include SAP,

PeopleSoft, i2, JD Edwards, Siebel, and Oracle Applications. The technology

adapters provide integration using standard technologies such as JDBC, JMS,

and Web services. The technology adapters include JDBC for relational

database, JText for text files, and Web services for service integration to

WebSphere Business Integration.

For a complete listing of available adapters, see:

http://www.ibm.com/software/integration/wbiadapters

The adapters typically include an object discovery component that allows for

metadata introspection and business object creation. Metadata introspection is

the process of retrieving information about the data, program objects, or

processes in an EIS.

8.2 Adapter-based integration

Integration using WebSphere Business Integration Adapters can be

accomplished by using an integration broker or a client service to initiate

requests or to accept events from the adapter. Through the use of the adapter

framework, the broker or client can integrate with different enterprise applications

using multiple WebSphere Business Integration Adapters.

202 Managing Information Access to an EIS Using J2EE and Services Oriented Architecture

Business objects are developed, and the adapter is configured to connect to a

specific instance of the EIS. The adapter is then deployed, and its service and

operations are exposed within an integration broker or client, which then makes

calls on the underlying EIS.

8.2.1 Adapter request processing interaction pattern

With request processing, the integration broker and clients send requests that

use a business object to the adapter through the adapter framework. The

adapter parses the incoming business object and makes the request specified on

the EIS using application-specific metadata and the business object content. The

adapter then returns the results, if any, of the call. WebSphere Business

Integration Adapters typically perform create, update, delete, and retrieve

functions using the verb attribute within a business object. Adapters can also

execute business processes in an underlying EIS (for example, to calculate an

order schedule).

Within the interaction pattern for request processing within WebSphere Business

Integration Server Foundation, the BPEL process makes a request through JMS

on the adapter. Figure 8-1 shows the components view for this interaction style.

Figure 8-1 Request interaction pattern components view

The adapter can process requests from a business process in two ways:

򐂰 The BPEL process can send a synchronous request to the adapter, where the

process sends a request to the adapter and waits for a response. This

process is also referred to as the

Hub Request interaction pattern, where the

hub in this case is the executing business process. The names of the port

types in the adapter service WSDL files reflect this pattern in their naming

convention.

򐂰 The BPEL process can also invoke an asynchronous request on the adapter,

where the process sends a request to the adapter without waiting for a

response. This process is referred to as the

Hub One Way interaction pattern.

The WebSphere Business Integration Adapter is created as a WebSphere

Application Server project within the WebSphere Business Integration tool set

and is configured to access the EIS with the appropriate business objects. The

WebSphere Business Integration

Server Foundation

JMS

WBI Adapter

Adapter Framework

M

Q

EIS

BPEL

Process