1. Jim Fawcett CSE791 – Distributed Objects Spring 2002
Microsoft .Net
Jim Fawcett
CSE791 – Distributed Objects
Spring 2002

2. Potential of the Web
The web started as an extended library of relatively static web pages ( ).
Web commercialization added a market place of products, e.g., Amazon.com, Dell.com, … ( ).
What’s next?

3. W3C View - Semantic Web
W3C’s Director, Tim-Berners-Lee sees a “Semantic Web”.
Web pages with semantic tags and catalogs of definitions and relationships between tags that convey “meaning” to computers.
The idea is to develop “automated web services such as highly functional agents.”
The focus here is a technical model for the web that supplies more detailed infrastructure.

4. The Service Bazaar
Microsoft and Sun seem to have a vision of the web as a bazaar of services, as well as products.
With the product model you make one large payment and get unlimited access to one product version, shipped over the web or via a physical route.
In the services model you make a per-use payment and get access to the most current version, over the web.

5. Web Services Provide a service over the internet
Support construction of distributed applications
Reuse model – a distributed application may use third-party services as part of their basic functionality.
Example – Travel Agency application uses scheduling services provided by airlines, trains, and hotels.

6. PC Magazine – Secret Services, 13 Nov 01

7. Web Service Components
XML – eXtensible Markup Language
SOAP – Simple Object Access Protocol
UDDI – Universal Description, Discovery, & Integration
WSDL – Web Services Description Language

8. PC Magazine – Secret Services, 13 Nov 01

9. XML Tagged, hierarchical markup language intended to describe data.
Schemas are used to verify that a given XML document satisfies some structural constraints.
eXtensible Stylesheet Language (XSL) is a presentation language used to support the styling and presentation of XML docu-ments.
XML documents can also be styled with Cascading Style Sheets (CSS).

10. SOAP Transaction Simple Object Access Protocol (SOAP)
XML data packed in soap wrapper, using HTTP protocol
Remote Procedure Call (RPC) model

11. WSDL Describes the capabilities of a web service
Tells other machines how to format their requests and responses to a web service
Defines a service’s binding to a network transport protocol, usually HTTP

12. WSDL According to the W3C:
Services are defined using six major elements:
types, which provides data type definitions used to describe the messages exchanged.
message, which represents an abstract definition of the data being transmitted. A message consists of logical parts, each of which is associated with a definition within some type system.
portType, which is a set of abstract operations. Each operation refers to an input message and output messages.
binding, which specifies concrete protocol and data format specifications for the operations and messages defined by a particular portType.
port, which specifies an address for a binding, thus defining a single communication endpoint.
service, which is used to aggregate a set of related ports.

13. UDDI A specification for an internet-wide registry of Web services.
Uses metadata
Details about the provider
Details about how to access the service
White pages
general information
Yellow pages
categories by industry, products, services, and locations
Green pages
technical details about invoking the services

14. UDDI Sample UDDI Listings Finding a business.
<find_business generic='1.0' xmlns='urn:uddi-org:api'> <name>IBM</name> </find_business>
Finding a service from a business
<find_service generic='1.0' xmlns='urn:uddi-org:api' businessKey='6827FE60-00E2-F6A9-F6C4-C AA77'> <name>UDDI Inquiry</name> </find_service>
Getting Details on a service
<get_serviceDetail generic='1.0' xmlns='urn:uddi-org:api'> <serviceKey>68280DC6-00E2-F E-C AA77</serviceKey> </get_serviceDetail>
(note, these will see if a company has a UDDI directory. The responses from the UDDI are very long in most cases.)

15. .Net Architecture

16. .Net Architecture Common language runtime library C# language
A set of base components
provided by the common language runtime
Networking, containers, GUI parts, …
Win Forms and Web Forms
New UI framework, simplifying UI implementation
ASP+
Active Server Pages supporting compiled server side components
ADO+
Database access components using XML and SOAP
Scripts can use common runtime library and can be compiled.

17. Common Language Runtime (CLR)
PC Magazine – Extreme Tech Web Site

18. Common Language Runtime (CLR)
Runs bytecodes in an Intermediate Language (IL) format. This is compiled, not interpreted.
Scripts now can be compiled and can use the services and components provided by the CLR.

19. C# Language Looks a lot like Java. Differences:
A strong analogy between:
Java Virtual Machine & C# code manager
Java bytecodes & C# Intermediate Language
Java packages & CRL components and assemblies
Both have Just In Time (JIT) compilers
Both support reflection, used to obtain class information at run time
Both languages lack generics
Differences:
Java and C# do have significant differences
C# has most of the operators and keywords of C++
C# has enumerations
C# plans to add generics in the second release of Visual Studio 7
C# code supports attributes – tagged metadata

20. What can you do with C#? Build console applications
Build windows applications
Uses a process similar to Visual Basic applications.
Build windows controls
Very like creating an ActiveX control
Create web server programs using ASP
ASP pages are a mix of HTML and script.
The HTML builds a presentation in the client’s browser
The script provides associated processing on the server.
Build web controls
Provide information to users via browser and web forms
Build web services
Provide information to other applications on other machines
Build .Net components

21. Support for Components
C# is designed to support components:
Properties, methods, events, attributes, and documentation are all first-class language constructs.
Any class can publish a set of events to which objects of another class can subscribe at run time.
Attributes, defined by the designer, can be attached to classes, methods, data members, or properties.
The compiler can be asked to generate XML documentation based on class attributes.
C# integrates with COM
Can build wrappers that create COM objects out of C# assemblies.
But C# assemblies themselves have a different architecture, and use manifests instead of the registry.

22. Base Components from the CLR
The Common Language Runtime library has components for:
String handling
Mathematical operations
Containers
File and directory access
Accessing the registry
Security
Building user interfaces and handling windows messages
Network and internet programming
Database access

23. Win Forms and Web Forms
Win forms build user interfaces using techniques borrowed from Visual Basic.
Significantly simpler than Win32, MFC, or WTL windows programming.
Much less powerful in Visual Basic. I don’t know yet how powerful Win Forms are in C#.
Web forms attempt to build user interfaces based on HTML pages.
Flexible and integrates well with distributed, web-based systems
Not as powerful as MFC programming.
Can you drop down to WTL or Win32 programming? I don’t know yet.

24. ADO+
Emphasizes the Data Set, which is a disconnected, in memory, copy of part of the database, which may have multiple tables.
This is a performance improvement that minimizes locking that used to occur with ADO recordsets.
You instantiate a DataSet, populate it from the database, and work on the DataSet.
Send back only changes to the database when you are done working with the DataSet object.
Transmission back and forth now uses XML, rather than COM marshaling, as with ADO.

25. ASP+ ASP code consists of pages of HTML and script.
ASP+ code does a lot of what the ASP scripts did using attribute tags.
ASP+ pages are compiled into into a .Net class the first time the page is requested. The compiled class is cached for future requests.
ASP+ pages can be changed without stopping the web server.
“Script” part of ASP+ pages can be written in any .Net language, not just VBScript or JavaScript.
Creation of ASP+ pages is directly supported by Visual Studio 7.

26. Performance? Microsoft .NET Pet Shop Lies, Damned lies and benchmarks?
New! Version 1.5 You need to see it to believe it! We implemented Sun's own J2EE best practices blueprint application, the Java Pet Store, using C# and Microsoft .NET. The result? The exact same application functionality was implemented in just 1/4 the code using C#/ASP.NET, and it performs up to 28 times faster than previously published benchmarks of the J2EE application.
Lies, Damned lies and benchmarks?

27. ECS Courses with .Net Content
Dr Furmanski offers courses on Mobile Computing that focus on .Net remoting
CSE791 - Distributed Objects:
Mostly COM based
Discuss C# and .Net Framework in 4 lectures.
Projects that may be done with either COM or .Net
CSE691/891 – Internet Programming (summer)
Almost entirely .Net centered
Focus on C#, remoting, ASP.NET, ADO

28. When can I start using .Net?
Visual Studio.Net has been released.
Generally available around March 1
Beta 2 has been installed in ECS clusters in Link 010 and 202.
You can no longer get the Beta2 from Microsoft downloads.
ECS is acquiring the license for MSDN. That implies:
In a few days you will be able to get CDs of the Beta2 from CIT
When they get the Visual Studio release version, probably in march, that will be available on CDs
I am trying to get the Computer Department in Schine to carry Visual Studio at the academic price
Books are starting to become available now – see the references on the next slide.

29. References C# Programming, Harvey et al., Wrox Press, 2000
Covers a lot of the .Net framework as well as C#.
C# and the .Net Platform, Troelsen, Apress, 2001
Professional C#, Robinson et al, Wrox Press, 2001
Microsoft .Net vs. J2EE, Jim Farley,
Comparison of .Net with Java 2.0 Enterprise Edition
Deep Inside C#, An Interview with Microsoft Chief Architect Anders Hejlsberg, John Osborn,
Interview with the principal developer of C#, who also was the author of the original Turbo Pascal.

30. More References C# Primer, Stanley Lippman, Addison-Wesley, 2002
C# Web Services, Banerjee et. al., Wrox, 2001
Professional .Net Framework, Hoffman, et. al., Wrox, 2001
Professional ASP.NET, Anderson, et. al., Wrox, 2001