Java Web Services in a Nutshell

An Example Web Service

Although it might appear from Figure 1-1 that there is a lot to learn before you can properly make use of web services, in practice, this is not true. Even though the technology is still relatively new, there are already tools in existence that simplify life for both the end user and the developer. To illustrate this, let’s look at how you might go about the task of developing a client application for the web service provided by Amazon.com.

First of all, how would you know that Amazon.com offers a web service? One way to find out is to visit their web site. In general, though, when looking for web services, you won’t know in advance all of the companies that might offer the service that you need, so you will most likely go to an electronic business registry and perform a search based on criteria such as industry sector, country of residence, etc. In Chapter 7, you’ll see exactly how businesses can publish information to a registry and attach classifications to it so that you can, indeed, perform a search based on various criteria, much as you would when looking for a business in the Yellow Pages.

Figure 1-3 shows the result of performing a search for Amazon.com in a UDDI business registry, which in this case is hosted by IBM.^[4] As it happens, Amazon.com has not applied any meaningful criteria to its entry in this registry (at least at the time of writing), so I did not find it by looking for booksellers. However, in an ideal world, this would be possible and, ...