Chapter 1: What are Web Services?

Overview

Imagine you are wrapping up a business trip in a strange city and running late getting to the airport. You eventually realize that you will not be able to make your flight. The helpful person who told you to take the expressway didn't realize it was under construction. Besides the bumper-to-bumper traffic, the exit you needed to take was detoured, and you weren't able to get over in time to make the turn.

You're thinking you can just continue on, show up at the airport, and take the next available flight. Of course, that may be in an hour or not until the next morning. How great would it be to know that the next flight you can catch is actually in the morning and you can better use your energy getting a room instead of continuing to fight the traffic? A room? It could take several phone calls and conversations before you find a nonsmoking room with a king-size bed and a data line like you need. How about directions to the hotel that bypass the construction traffic? You also need to adjust your calendar to cancel or reschedule your early morning appointments the next day.

And wouldn't you like to know where you could find a drive-through Starbucks on the way to the airport in the morning?

Imagine being able to do all these things with one or two simple requests from inside your vehicle. Web services can make this possible. Web services are processes that can be accessed by other systems over the Internet. Of course, this doesn't just happen magically on its own. Solid designs and implementations are necessary for effective Web services. This book is intended to assist you in making this scenario, and many others like it, a reality.

We start in this chapter by introducing the concept of Web services and how they differ from what we have been doing. For this, we need to look back at how we got here and the obstacles we have encountered. Next, we analyze what it means to share information and processes between users and systems, followed by a look at the evolution of the Web services solution. Finally, we look at some scenarios to help us distinguish this solution from others that may seem similar. These topics lay a conceptual foundation for the remaining chapters, which cover everything you need to know to design and build your own Web services right now.