Microsoft .Net

1. Microsoft .Net Jim Fawcett CSE687 – Object Oriented Design Spring 2002

2. 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.

3. 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.

4. PC Magazine – Secret Services, 13 Nov 01

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

6. PC Magazine – Secret Services, 13 Nov 01

7. 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 documents. • XML documents can also be styled with Cascading Style Sheets (CSS).

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

9. 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

10. 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.

11. 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

12. 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-C6113993AA77'><name>UDDI Inquiry</name></find_service> • Getting Details on a service • <get_serviceDetail generic='1.0' xmlns='urn:uddi-org:api'><serviceKey>68280DC6-00E2-F664-135E-C6113993AA77</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.)

13. .Net Architecture • http://www.dotnet101.com/articles/art014_dotnet.asp

14. .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.

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

16. 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.

17. C# Language • Looks a lot like Java. • 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# code supports attributes – tagged metadata • C# plans to add generics in the second release of Visual Studio 7

18. 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

19. 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.

20. 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

21. 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.

22. 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.

23. 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.

24. Performance? • Microsoft .NET Pet Shop • New! Version 1.5You 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? • http://www.gotdotnet.com/team/compare/petshop.aspx

25. 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 • CSE791 – Advanced Windows Programming (summer) • About 60% of the course will be .Net content, mostly WinForms • CSE691/891 – Internet Programming (summer) • Almost entirely .Net centered • Focus on C#, remoting, ASP.NET, ADO

26. When can I start using .Net? • Visual Studio.Net has been released. • Final Release is out, in the Schine Computer Store for $99 + tax. • Beta 2 has been installed in ECS clusters in Link 010 and 202. Final release will be installed very soon. • You can no longer get the Beta2 from Microsoft downloads. • You can get the .Net Platform SDK which has command line compilers etc. • Books are starting to become available now – see the references on the next slide.

27. 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, www.java.oreilly.com/news/farley_0800.html • Comparison of .Net with Java 2.0 Enterprise Edition • Deep Inside C#, An Interview with Microsoft Chief Architect Anders Hejlsberg, John Osborn, www.windows.oreilly.com/news/hejlsberg_800.html • Interview with the principal developer of C#, who also was the author of the original Turbo Pascal.