.NET. Inf 5040, Outline. Gyrd Brændeland, Sharath Babu Musunoori, Åshild Grønstad Solheim

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1 .NET Inf 5040, Gyrd Brændeland, Sharath Babu Musunoori, Åshild Grønstad Solheim Outline Introduction An overview of.net framework architecture More focus on.net core components.net features Web services including an example of ASP.NET Summary 1

2 What is.net? A new environment for developing and running software applications, featuring ease of development of webbased services, rich standard run-time services available to components written in a variety of programming languages, and inter-language and inter-machine interoperability. The versions:.net 1.0 released January 15th 2002 Current version is 1.1 Beta version 2.0 available The.NET space Web services Designed to be accessed directly by another service or software application Interaction through XML and SOAP Supplied services such as: NET Passport,.NET Alert, MapPoint Deployment platforms Server products: Windows Server, Microsoft BizTalk Server, Microsoft Commerce Server, Microsoft SQL Server, ++ Support and use web services and process XML Developer platform: The.NET Framework Our main focus 2

3 Developer platform contents of the.net Framework I CLR - Common language runtime Large collection of framework class libraries A number of tools Developer platform contents of the.net Framework II CLR - Common language runtime Virtual instruction set to isolate from particular processors (like JVM). Enables components that require tight integration with the specific underlying platform (unlike JVM) Implementation of the common language infrastructure (CLI) specification, adding COM+ interoperation and Windows platform access service Supports several languages Large collection of framework class libraries Frameworks partially interfaced, partially class-based. A number of tools Editing, building or debugging across multiple languages Remote debugging for distributed systems Supportive tools for tasks such as modeling, browsing or documentation Third-party tools for analysis of performance and resource consumption Visual Studio.NET integrates most tools for the.net framework 3

4 ECMA standard: Common Language Infrastructure A way to deal with the problem of language interoperability What is What in.net Framework Architecture Common Type System (CTS) Type Safety (TS) Managed code execution Side-by-side execution Common Language Runtime (CLR).NET is different from CORBA, Java Intermediate Language (IL) Support for extensible metadata Support for COM and platform interoperation 4

5 Common Type System (CTS) Super set in the type space CLI-complient code over CTS space CLS is a strict CTS subset Interoperate the code implemented in different languages CLS consumer / CLS producer / CLS extender Object interface String array class MarshalByRefObject Value Type class ContextBoundObject Enum enum struct Boolean, Byte, Int16, Int32, Int64, Char, Decimal, Guid, Single, Double, DateTime, TimeSpan class Top-level CTS type hierarchy Common Language Runtime (CLR) Compiles IL code into native code, and execute the code Include services like. 5

6 Putting all in a different way Assemblies, AppDomains, and Reflection Assembly: A set of files (dlls, exe, html etc) in a directory hierarchy resembles a jar file, or can be an application or a library enforces many security restrictions either private or shared among multiple applications each has a version number, compatibility version Application domains: aims to isolate an application from other applications Scope of loading and unloading of assemblies Context: divides AppDomains Reflection: support access to the metadata of loaded assemblies metadata include type structure, attributes enables creation of instances of types enables invocation of methods 6

7 Remoting Combines context and reflection infrastructure Support for communication styles and patterns Proxies, channels and messages as building blocks Remote method calls Remote access styles: SingleCall: incoming requests are served by new objects. Singleton: incoming requests are served by a single server object. ClientActivatedObject: reference to a remote object is maintained until the client is finished with it. Reference to remote objects (like Java RMI) Lease-based handling Renewal / expire of remote references Distributed garbage collector.net security facilities Web application security ASP.NET supports authentication schemes such as Kerberos Role based security Authentication: SSL/TLS client certificates ASP.NET security architecture Custom authentication or authorisation providers Evidence-based security Code access security (CAS) Cryptography - supported algorithms: Asymmetric encryption - RSA and DSA; Symmetric encryption - DES, TripleDES, RC2; Hashes - MD5, SHA1. 7

8 Web services with.net Web services with.net Based on XML (extensible markup language) Normally uses SOAP (Simple Object Access Protocol). An XML-based protocol for invocation of remote objects typically uses HTTP SOAP - summary from previous presentation (Group 5): SOAP specifies only a message from a sender to a receiver Anything beyond this is unspecified (e.g. using client/server model) Three main parts: Envelope Encoding Rules RPC Representation 8

9 Web service example Create simple web services with Active Server Pages (ASP).NET Example: web service for addition: WebService Language="VB" Class="MyMath" %> Public Class MyMath Public Function <WebMethod()>Add(a As Integer, b As Integer) As Integer Return a + b End Function End Class First line addresses ASP.NET The attribute <WebMethod> tells ASP.NET that the method is Web callable Then ASP.NET does the necessary work for the method to support SOAP The service can receive and send SOAP messages J2EE vs.net Java 2 Enterprise Edition (J2EE) and.net Platforms for developing enterprise applications Built-in multi-language support:.net CLR supports multiple languages JVM supports only java. Efficiency.NET source => IL (Intermediate Language) => machine code (install or load-time) Java source => byte code and interpreted by JVM, but more efficient JVMs may translate into machine code. Language Small difference between C # and Java 2 Derived from C and C ++, garbage collection, attributes, metadata Platform dependency Java: In principle platform independent.net: Microsoft does not support other platforms, but C# and CLI open standards. MONO: Open source implementation of.net Framework for Linux. Open source Some open source java compilers. Open source implementations of CLI: Mono project ( Open CLI Library project (sourceforge.net/projects/ocl) 9

10 Summary Overview of.net CLI (Common Language Infrastructure) and C#: ECMA standards CTS (Common Type System) and CLR (Common Language Runtime). Assemblies the.net software components AppDomains, reflection and remoting Security Web services Comparison of.net vs J2EE References Jim Farley. Microsoft.NET vs. J2EE: How Do They Stack Up? January Student presentation: SOAP, group 5 C. Szyperski. Component Software. Beyond Object-Oriented Programming. Addison-Wesley Understanding.NET framework at a glance. Bertrand Meyer. NET is Coming, Pages 92-97, ISSN: