1. The future of distributed systems architecture
.net Web Services
The future of distributed systems architecture
Bradley Gessler
Booze Alan Partner

2. Agenda Before web services Introduction Web service examples Messages
Code demonstration
Future
Assignment

3. Before Web Services
Raw Byte Streams
RPC
RMI
DCOM
“Screen Scraping”

4. Introduction to Web Services
XML based RPC
Interfaces that are defined via XML
Uses messaging scheme
Service Oriented Architecture
Usually HTTP based
Firewall friendly
Can use other channels

5. XML Web Services Client invokes XML Web Service
Internet
Client invokes XML Web Service
Web Service receives and processes request
Web Service sends client a response

6. Channels Protocol used to transmit web service messages HTTP SMTP FTP
MSMQS

7. Protocols All standards are based on XML
This has made interoperability possible
Current standards are still evolving
Mature enough for simple enterprise applications
New protocols are evolving to enhance current protocols
Security standards
Transactional standards

8. SOAP Simple Object Access Protocol Used to invoke web services
Send/receive messages to and from web services
Describes the methods, arguments, and results of a method call
Envelopes

9. WSDL Web Services Description Language
Describes the interface of the web service
Methods
Arguments
Return Values
Variables
Types
Simple Data structures
Arrays

10. UDDI Universal Description, Discovery, and Integration
Web service directory
Not widely implemented

11. Real world XML web services
Web Services Examples
Real world XML web services

12. Web Services Zip Code Web Service MapPoint.net
MapPoint.net

13. Consuming a Web Service
Visual Studio.NET Demo

14. Messages
Its a Messaging World

15. Messages Packet of meaningful data SOAP Message
Similar to IM messages work

16. Synchronous & Asynchronous
Synchrony
Synchronous & Asynchronous

17. Synchronous
Client
Web Service

18. Asynchronous
Client
Web Service

19. Reliability Unreliable Reliable Idempotency
Messages might not be received
More then one of the same message may be received
Reliable
Idempotency
Make sure your web service methods are idempotent

20. Visual Studio.net Demonstration
Creating a Web Service
Visual Studio.net Demonstration

21. Creating a .net Web Service Prerequisites
Required
Web Server
IIS 5.0 or greater
Microsoft .net Framework 1.0 or greater
Recommended
Visual Studio.NET 2002 or better
Other Web Service Platforms
Apache Tomcat, J2EE

22. Web Service Business Value
Less infrastructure requirements
Developers can focus on solving business problems

23. Future of Web Services Enterprise Connectivity
Already used internally by many organizations
Starting to gain acceptance as a way to connect organizations to one another

24. Service Oriented Architecture
Encapsulate all enterprise applications with web services
Consume web services from various systems and applications for various uses
Extremely flexible, scalable, and interoperable

25. Future of Web Services Windows Codename “Longhorn” “Indigo”
Integrated messaging system
Support Multiple Channels
Web Services
MSMQ
And more…
Abstracts the complexities of web services much like what the Visual Studio.net IDE

26. Assignment Consume the zip code web service
Create a windows form that gets the name of the city based on a zip code given by the user
Display the city of the given zip code to the user

27. Resources MSDN .net Overview SOAP Example http://msdn.microsoft.com/
.net Overview
SOAP Example

28. Questions