internet commerce

The "Teach Yourself" series has done little to impress me until the arrival of this book. XML-based web services are getting traction as a truly standard way of enabling the service-oriented systems architecture. An architecture where systems can be built to expose services in such a way as to make it easier to integrate enterprise systems has been built many times already, but always ending up with constraints related to programming language, operating system and hardware. This book provides a good introduction to XML-based web services components including XML schema, WSDL, UDDI, SOAP and HTML with a comparison to the past attempts including DCOM and CORBA. The code examples require some analysis but are pretty helpful once you've taken the time to decode the XML and the scenario examples / case studies provide an interesting context to see how XML-based web services can be applied.

As someone who knew ABSOLUTELY nothing about web services when I started, this book was the best of the 1/2 dozen titles I perused because it balanced high level understanding with the nitty-gritty and code examples. I found this book far most useful than titles such as 'Web Service: A Manager's Guide' and '.Net Web Services for Dummies'.

As someone who is not particularly technical, the code segments were still very useful in understanding what is going on. Without looking at a little code, understanding web services and its components becomes too esoteric. Why would you just describe an elephant when you can also provide a picture.

As someone who was just trying to understand web services and had no interest in comparing specific vendors' web services offerings, the chapters on commercial tools such as Apache Axis, Java, .NET, IBM Websphere and BEA Weblogic, and their specific pros/cons was not terribly interesting to me. But I could see how they would be valuable to an IT Professional.

The book does not really take 24 hours. Overall, I spent 9 intense hours working through this book to developing a good grasp of the technology. I recommend the opening chapters of 'Understanding .NET' by Chappell as a great supplement. Chappel gives great brief high-level descriptions on the components of web services and how they came about.

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To learn how to build and use web services, you first must determine what they are and how they differ from current technologies used in the development and use of web pages. With the exception of being based on eXtensible Markup Language (XML), they are only different in degree from widely used web technologies such as Active Server Pages (ASPs) and Java Server Pages (JSPs).
The authors do a good job of explaining what web services are and how they differ from other technologies. They also do not fall victim to the evangelical bug, being very explicit in pointing out the disadvantages of web services as well as the advantages as a chapter is devoted to each point. Another chapter is devoted to comparing how web services differ from other technologies such as ASPs, JSPs, Common Gateway Interface (CGI), Common Object Request Broker Architecture (CORBA) and Java Remote Method Invocation (RMI).
The middle section of the book is devoted to describing the architecture of web services , the basics of XML, how web services communicate using XML and Simple Object Access Prototcol (SOAP), how web services are described using Web Services Description Language (WSDL), and how to advertise a web service using Universal Description , Discovery and Integration (UDDI). While not detailed, it is a complete introduction to all of the steps you must go through to create a complete web service that others can use.
The third section is devoted to describing several tools that can be used to build web services. Commercial tools such as Apache Axis, Java, .NET, IBM Websphere and BEA Weblogic are covered and the authors are to be commended in also showing how they can be built using inexpensive and free toolkits. Finally, the last section covers topics such as the interoperability of web services, how security is included in web services and what some of the future trends in web services may be.
This book is an introduction to web services, so it is not possible to learn all of the specifics you need to build complex web services from it. However, if you are a beginner, there is enough information to get you started and to help you make decisions concerning whether you want to start building them.