I am doing XML and web services for a while.
There is first the problem of the XML schema design. I think we have 
got plenty of pointers. Because not all toolkits support all XML 
schema features, it is likely that using basic XML schemas features 
only is a very good approach.
The most important point I think is to start from the XML schema to 
build your web service and not from the existing implementation. I 
think you do.

But there is a more fundamental thought. Java, C# are not XML, these 
languages are object oriented and you will likely use internal object 
models in your implementation. You will have to map your XML to 
objects.
On the other side of the service, you will likely use a relational 
database. Guess what, Java, C# are not relational minded either. You 
will end up with a mapping between the Java code and the database too.

There are 2 impedance mismatches in Java and C# when dealing with XML 
based services and relational databases.

There are tools for making these mappings a configuration problem 
more than a coding problem. But anyway, a large part of the 
development cost will go away in those mappings. Maybe a new language 
and maybe less object orientation orthodoxy will bring a definitive 
best practice. Nothing mainstream yet on my radar.

The selection of the tools which will do the mapping for you is 
critical. You must be aware that some Soap toolkits will produce 
objects that you might not be able to persist in a DB using your 
favorite object-relational mapping engine. Ideally, you should be 
able to map an XML message to any kind of object model. Some toolkits 
are allowing this nicely, the majority does not.

I do not want to let the impression that all web services are only 
CRUD-like, data access only. It is a best practice to abstract 
business logic along with the data in your services, if useful.
But anyway, this is a critical architecture decision for future cost 
and agility of your services portfolio.

In my current Java project, I have started to use JiBX for the 
XML/Java mapping and Hibernate for the O-R mapping. While Hibernate 
is now accepted by the industry, tools like JiBX are really unusual 
and your favorite J2EE vendor might tell you that you are crazy.

Robin.

--- In [email protected], "Biske, Todd" 
<[EMAIL PROTECTED]> wrote:
>
> A colleague and myself have been trying to bridge his world of XML 
schemas, coming from a database modeling background, and my world of 
Web Services, and it hasn't been easy.
> Thoughts?  Any pointers to some good guidance in this space?  
Thanks-
> Todd Biske
> Software Infrastructure Engineering
> A.G. Edwards Technology Group, Inc.
> V:(314) 955-6254 F:(314) 955-4055 E:[EMAIL PROTECTED] 








------------------------ Yahoo! Groups Sponsor --------------------~--> 
Get Bzzzy! (real tools to help you find a job). Welcome to the Sweet Life.
http://us.click.yahoo.com/A77XvD/vlQLAA/TtwFAA/NhFolB/TM
--------------------------------------------------------------------~-> 

 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/service-orientated-architecture/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply via email to