Application endpoints are the true lifeblood of an EI solution. The ability to initiate
and respond to application processes differentiates EI from normal integration.
Although database and file endpoints provide needed methods of integration,
responding to events and processes within an application provides real integra-
tion power. This is because application endpoints provide more than just data;
they also provide the context of that data. For example, if a particular step in an
application process is to save an order and you can intercept this step, you can
initiate actions outside the application. As a result, not only will you know that
an order has been updated, you will know it occurred within the application’s
fill order process.
Knowing this information allows you to create an EI solution that is signif-
icantly smarter. Returning to our example, the outside application can then
respond appropriately to a filled order. Obviously, these endpoint types are
much more difficult to implement. Not only do you have to respond to the
event, but you also have to capture the data and the context in which the event
occurred. Thankfully, the vendors of most large systems have already written
adapters that simplify integration to the major EAI tools. These adapters are
examples of application endpoints.
This chapter will show you a number of methods and techniques that you
can use to integrate to applications at this level. You might consider this event-
based programming implemented at the organizational level. This chapter will
also demonstrate how to accomplish the same effect in other ways in situations
where adapters are not available. We will start with a very simple endpoint and
progress toward more advanced methods.