JBI is the new integration API introduced in the J2EE world. It is a great enabler for SOA because it defines ESB architecture, which can facilitate the collaboration between services. It provides for loosely coupled integration by separating out the providers and consumers to mediate through the bus.

The NMR provides a common integration channel through which the messages flow. Services are published in the bus using the WSDL standard. Providers and consumers are the different roles taken by the integration components with respect to the bus, when plugged into the JBI bus. Message exchange takes place through different MEPs, each providing different levels of reliability.

The next chapter will introduce a JBI container. Be ready to wet your hands with some code too—to build and deploy your first JBI sample.