Service Oriented Architecture For Dummies®

Chapter 7. Dealing with Adapters

In This Chapter

• Discovering the true nature of adapting

• The ties that bind

• Deciphering adapters

• Actually building adapters

Adapters make SOA possible. No adapters, no SOA — it's as simple as that. More than anything else, SOA is about being able to reuse the business applications that you already have. In order to do that, you need to add interfaces to these applications that allow you to directly invoke — from any other program, mind you — the functions these applications contain. The SOA adapters provide these interfaces.

The easiest way to understand adapters is to realize that all software of any kind has an interface of one kind or another. It doesn't matter what the software does. And not just business software, but any kind of software — word processors, games, PC calculators, Web sites, and programs run by NASA to calculate the correct trajectory for a space probe as it passes Jupiter on its way to Saturn — they all have interfaces. Gobs of them.

All software does something — you would hope — but it does what it does only when some user (or possibly another program) tells it to. The way that the user or the other program gives the software the command is through its interface. And the way the software presents information back to the user or a computer program is also through its interface. That, in fact, is precisely what an interface is — it's the connection point that a program has with a user or some other program. For example, a person might ...