Web Services Tutorial 2
In this tutorial will give explore XML Web services
further? You will consider the application
of Web Services in E-Commerce.
Required Software
For this tutorial, you will need access to Microsoft
Internet Explorer.
Breakdown of Tutorial
This tutorial consists of the following tasks:
- Some
learning checkpoints of your learning.
- Exploring
some the Web Services that are exposed through a UDDI.
- Further
learning checkpoints and reflection on suitability of Web Services.
Exercise
1: Learning checkpoints
Through the learning material, you have been introduced
to the components and protocols relating to XML Web services. We will now
explore some practical examples of real-life Web services to help you to master
these concepts.
Use your notes and other resources to answer the following
questions:
|
What does UDDI stand for? What is the purpose of
a UDDI in relation to Web services? |
|
|
|
What is the difference between XML and WSDL in terms
of Web services? |
|
|
|
What does SOAP stand for? What functions do SOAP
and HTTP perform within a Web service? |
|
|
Exercise 2: Explore some Web Services
Many .NET Web services already exist. Using Internet
Explorer, navigate to the following Web service: http://ws.cdyne.com/whoisquery/whois.asmx
You should see a summary page, which indicates the
functions which this Web service has exposed (see figure A below). This page
is automatically generated by a component of the .NET framework.
·
Click on the function getwhois.
This function returns the registration details for a given Web site. You will
be provided with an interface to test out this particular function.
·
In the next page enter a web site
you know e.g. www.ebuyer.com. You can
use the password 0 for test purposes. Click the invoke button to execute this
Web service operation. The Web service should return a dynamic XML page with
the data that is returned in response to your invocation of this function.
·
Go back and click on the links
that says service description – what basic language is this in? What is the
specific acronym used to describe the specific format of the code you are
looking at?
·
Now try the same process, but
with an erroneous URL – check the XML response.
·
Have a look at some of the Web
services below, test them out to see if you can get them to operate:
http://samples.gotdotnet.com/quickstart/aspplus/samples/services/MathService/VB/MathService.asmx
NOTE: You may need to find a password to get some
of these Services to function
Let us visit to a Web site which allows organizations
to register, expose and discover Web services. The URL below is the location of Microsoft’s
UDDI service:
·
Click the search link to the left
of the Web page. On the next page,
select VS Web Service Search Categorization as your search category. Now choose
any sub category then click the services tag. You should be able to test these
services by clicking on any link which has an .asmx extension.
·
Spend a few minutes browsing around
this site and take a mental note of any observations you make.
Exercise 3: Explore suitability of Web
Services in
|
What are your first impressions of the Web services
you tested? Could these functions have been achieved using a different
middleware approach? |
|
|
|
List below, 5 e-business scenarios for which XML
Web services are ideally suited (both consuming and exposing) |
|
|
|
Given the examples you have just seen, can you identify
5 challenges that will face organizations who are taking up XML Web
services (both consuming and exposing)? |
|
|
|
What were your impressions of Microsoft’s UDDI registry? Did you make any specific observations? Is this service being used as intended, are there
any potential problems with this approach to a Web services directory? |
|
|
|
List below, 5 e-business scenarios for which XML
Web services are ideally suited (both consuming and exposing) |
|
|
|
Given the examples you have just seen, can you identify
5 challenges that will face organizations who are taking up XML Web
services (both consuming and exposing)? |
|
|
Back to home