11.4 Summary

The B2B and J2EE architectures each have distinct advantages. The B2B architecture is emerging as a solution for integrating business objects over the Internet or other WANs. This makes it an attractive option for integrating business objects, although the relevant standards are still evolving.

J2EE has significant momentum and a large share of the application server market. Web-based applications benefit greatly from J2EE because developers can focus on business logic and not spend time developing infrastructure that provides no direct business value.

The B2B and J2EE architectures differ mainly in their views of distribution. The B2B architecture views distribution as integrating applications running on different platforms and from different vendors in an asynchronous manner. The J2EE architecture views distribution as integrating application components and providing support for distributed transactions in a synchronous manner.

A transactional architecture, such as the one supported by the J2EE architecture, is recommended when system development is driven by the following scenarios.

• Business objects are deployed on a single machine or on a high-performance LAN.

• Business objects are tightly coupled .

• Data integrity is an important issue and transactions may span multiple business objects and legacy components.

A nontransactional architecture, exemplified by the B2B architecture, is more appropriate in the following situations.

• A business object may be replaced in the future with a third-party component or application.

• Asynchronous communication between different applications running on possibly different platforms is required.

• Communication is B2B or A2A.

B2B and J2EE are not mutually exclusive as business object integration approaches. For example, applications can be developed using the J2EE framework and communicate with other applications using the B2B framework, as shown in Figure 11-4. J2EE applications communicate synchronously with a BSR interface that creates and sends outgoing BSRs and receives and interprets incoming BSRs. The BSR interface communicates asynchronously with other BSR interfaces, using the MOM infrastructure ”hiding all OAGIS and MOM details from the J2EE applications. The BSR interface can be shared by one or more J2EE applications. This BSR interface can be custom developed or can be provided by the framework component of existing XML messaging efforts, such as BizTalk, ebXML, or RosettaNet (see Section 9.5).

Figure 11-4. Integration of the B2B and J2EE architectures

As always, you need to select the architecture that best fits your requirements, business goals, and resources. This architecture needs to work today, as well as in the future.