Chapter 6 

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6.3

The J2EE 1.4 platform provides several technologies for integration, and you can

combine them to fit your integration requirements. These technologies, together

with the other platform capabilities, give you a rich platform for designing an inte 

gration solution. IT architects face the challenge of combining the technologies in

the most effective and flexible manner possible to create an integration architec 

ture that can adapt to changing business needs and strategies. 

Often, enterprises attempt integration as a  one off  solution that is, they

treat each integration problem as a unique instance with its own special solution.

With this type of approach, an enterprise integrates each system in an individual,

custom manner not the most efficient or effective integration approach. It is far

better to have an integration architecture that grows with the needs of the enter 

prise. The J2EE platform, with its extensive support for Web services, makes such

an architecture possible. A J2EE application server acts as the universal connector

between the EIS systems and new EAI applications. (This chapter uses the term

EAI applications to refer to applications specially designed to solve the problems

of integrating enterprise applications.) In a sense, the J2EE application server is

the integration hub. The data model in the application server becomes the canoni 

cal agreed upon data model to which all others EISs and new EAI applica 

tions adapt. Figure 6.4 shows how this might look from a high level. 

A good integration architecture consists of a set of  integration layers  each

of which provide certain quality of services. By integration layer we mean the

interface or endpoint at which distinct systems intersect. Enterprise architects and

software developers must decide how to implement these various integration

layers in the most suitable manner. Generally, the requirements of each situation

drive the choice of integration layer. For example, the adventure builder enterprise

uses Web services as the integration layer for its supply chain. As a result, all

interactions with its suppliers must happen through the Web service interfaces. 

E

The integration layer defines the interface between the EIS systems and new 

applications, thus exposing an EIS system to an application. 

E

An integration layer needs to be the stable point in your system the fixed 

standard against which new applications are programmed. While both the new 

application and the existing EIS may change, the integration layer should re 

main the same. Otherwise, changes in one place will require changes to numer 

ous dependent systems.