Customer Reviews

Using XML with Legacy Business Applications

5 star:		(7)
4 star:		(1)
3 star:		(0)
2 star:		(0)
1 star:		(0)

 

 

A lot of IT people are busy making different applications running on different platforms "talk" to each other. XML was invented as the "Esperanto" of the IT world to get these systems to understand each other. In practice however it just isn't that simple, as most of these applications don't talk XML yet, until this book.

This book is a real do itbook. It does not teach you XML or XSLT but shows you how to use it. What I especially liked is that he discusses his design considerations, he wants you to understand the whys. Once he thinks you know the basics he goes back to his basic design and improves it to make it make it fully reusable and modular, making it even beter.

Mr. Rawlins gives you toolbox of utilities, with the source code, that can become the building blocks for your own application integration system.

I have not come across a book with as much usable code in my IT career. We have already redesigned quite a few of our systems because of it. If you are into connectivityyou cant be without this book.

Ps. The word Legacy in the title does not imply big mainframes.

Easy to read, in a refreshing unpretentious style, Rawlins explains numerous complicated concepts associated with using XML. Especially useful are the chapters covering the conversion of EDI formatted data into and out of XML and the converting of one XML format to another XML format. The inclusion of Java and C++ considerations in appropriate chapters provides excellent practical advice.

XML purists may well decry this book. XML has captured overwhelming mindshare amongst developers as the preferred means of data interchange between programs. Plus, for recording to and from files, if you are starting a project with no legacy hangups, XML is often used.

Notice the caveat. Unfortunately, you as a developer cannot often start with a blank page. You may have to cater to existing data being stored in various formats, like CSV (Comma Separated Values). Or you have flat files with each line like "a=b". Or perhaps existing apps talk via EDI, which is quite common in certain industries.

Most XML books gloss over such details. Usually for good reason. Typically, they are trying to educate a reader who has never used XML. So for pedagogic clarity they deprecate these impedance mismatches. Which is correct, but of little help to you right here and now.

Rawlins tries to fill this gap. He assumes you know XML. The book rapidly goes into the grubby little details of how to overcome those impedance mismatches. Mundane but necessary. Somewhat inelegant manipulations, by the very nature of the topic. The book fills a real need. Though I suspect that many readers, and maybe even the author, wish this need will eventually evaporate. The pragmatists amongst you won't see this as imminent. The reality is that we will all have to support legacy apps indefinitely. Which should generate a steady demand for this book.

Mike Rawlin's book deals with the reality that legacy business applications are not readily converted to processing XML-formatted information. While XML works fine as the interchange format, you need to convert between that interchange format and the format your applications understand. Mike covers all of the minor nuances that you need to consider, presents a wealth of knowledge in an easily-understood format, and provides examples to boot.

Rawlings does a first-rate job of conveying elegant solutions to very arduous problems. If you find yourself in the trenches trying to bridge the technology gap between modern tools and older EDI or flat file based systems - this is your book. Those without the budget for a commercial product will especially appreciate do-it-yourself practical code and easy to follow examples.

This book provides practical advice and examples on integrating XML into existing business systems. The book is easy to read and follow. The approach of the book is to break the problem down into a chain of simple problems, addressing each as a data 'filter'. The end result is to connect the input/output of a legacy system with the input/output of an XML parser.

I recommend this book to anyone faced with the problem of using XML to extend the reach of existing applications.

I have just this past week had the pleasure of reading briefly through Mike Rawlin's book on this topic. Mike has done an outstanding job of taking a technical topic and addressing it in a very clear, succinct writing style that makes even the most obscure EDI/XML concept accessible to the reader. I believe this book should be on the desk of every EDI professional challenged with not only continuing to support current EDI environments, but trying to understand how to use XML in that environment.

Great job Mike! Congratulations on a job very well done! I stand in awe of the effort and discipline coupled with your knowledge and experience that resulted in this book! Hats off!

This book is very unique. The aim of this book is not to develop a new XML application from scratch. Instead, this book gives us many practical ideas to make existing business non-XML applications �gXML-aware�h. Though XML has become a first class data format in the world, this book is very useful for many business application developers who are still working with legacy applications with proprietary input and output. This book provides good design principles and methodologies for working with various existing data format such as CSV files, flat files, and EDI (X12) transactions. It also covers XSLT, XML Schema and other standard technologies. You can see rich pseudo code (I like it after I understood the syntax) and its implementation using Java and C++ are included.