Write Your First Web Services Client Part 1: Finding and Testing Services

I have realized that most of the available tutorials about Web Services for newbies show how to write a first Web Service example (usually “Hello World”, or a fake “Currency Exchange”), deploy it on the local server and next how to write a Web Services client for it, but actually not really how to use existing Web Services, which are already available on the Web. Is this really what a newcomer expects to learn when hearing for the first time about Web Services technologies such as XML, SOAP or WSDL? How to write fake services, which are not of any practical use for his/her applications or get confused with XML details? I do not really think so! Also because of this approach, newbies might have a perception that Web Services technologies are unnecessary complicated and difficult, not worth of investing their time. At the end of the day if I have to write all this code myself to get a Web Service example up and running, is it not simply a better idea to connect directly to my own database, write my own class, java bean or anything what is simple, instead of using Web Services. So lets try to make a practical 2 minutes Web Services tutorial for newbies, which actually delivers something real, which cannot be extracted from the local database or coded in an internal class of the application. And the most important, lets use not fake ones, but real Web Services!

I assume you might be working as a Web developer and have learned somewhere about Web Services as a technology allowing to call some functionality over the Internet. Now you would like to see it working and understand what would be benefits for your company without investing a huge amount of time for studying all the tiny bits and baits of XML format, or SOAP and WSDL protocols, but just to make a few simple steps to start using them. You have some basic idea about programming and you would like to get some cool feature for a website of your customer. Then in this short Web Services tutorial, I will show you using step by step example how to find such a cool feature at seekda and how to test it with tools provided by us.

As I am personally living in Innsbruck, Austria and Tirol is mainly about tourism, then I imagine that my hypothetical Web development company has been contracted by a local hotels resort from Innsbruck to build them a website. As these are several five and four stars hotels grouped together, with many attractions, they can easily afford to spend a lot of money to have a cool website with various catchy functionalities. So why not get some nice features with a minimal effort. Lets get Web Services to do the whole work for us in the background. Being myself often a tourist I imagine that somebody coming to visit Innsbruck would like to see the current weather conditions directly on the website of the hotel in which he/she is going to stay. So lets check at seekda if Web Services can do the job for us:

1) I am going first to use seekda to search if there are available any “weather” related public Web Services. I am getting 163 services as a result.

2) Reading through the first three returned results, I assume that GlobalWeather Web Service from webservicex.com should suit my requirements and do the right job. It is free, works for the whole world for major cities (I hope Innsbruck is a main city, but we will have to check it by invoking the service). But first, lets check details of this service (click view details link).

3) I can find out from the Web Service Details tab that the availability of this Web Service has been so far 97 percent. Read our previous blog post on Monitoring the Availability of Web Services to learn how to interpret this information. Generally, for our example this service seems to be perfect.

4) Then lets try if this Web Service works for Innsbruck. Select tab Use Now and then pick up the GetCitiesByCountry operation. Here you must invoke this service with parameter “Austria”

5) As a result of Web Services invocation we can see for which Austrian cities, this Web Service is capable to provide results. When reading through the result list you can find out that the service can provide current weather information for Innsbruck-Flughafen (which actually mean Innsbruck Airport in German).

6) So lets now call the Web Service operation, which is called GetWeather. Here I have to provide the name of the city (which is “Innsbruck-Flughafen” and name of the country, which is “Austria”)

7) Finally I am getting results of Web Service invocation. We have quite a nice weather right now with outside temperature 48 F (9 C).

In the second part of this Web Services tutorial, I will show an example how to integrate a Web Service found through seekda into your own application or a website.