In this chapter we have spent a lot of time covering gateways and their role in integrating external clients with the ESB. Specifically, we covered:

In many of these sections we have only touched the surface of what is possible, giving a flavor of the gateway capabilities with the hope that this will encourage further exploration.

Gateways play an important part in extending the reach of the Enterprise Service Bus, allowing the ESB to provide services which are reachable from external clients and, as a consequence, allowing it to intercept and augment communication between existing services.

Now that we've given a broad introduction to gateways we are ready to move on to our next topic and learn what part the registry plays within the JBoss ESB—the topic of the next chapter.