1. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott COMP6325 Advanced Web Technologies Dr. Paul Walcott The University of the West Indies Session 3 – Building Enterprise-scale Web-based Applications Summer 2008

2. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Objectives  In this session the student will: Discuss the.NET and Java Enterprise Edition 5 frameworks Construct a simple C# program Compare and contrast enterprise-scale web-based application frameworks

3. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is an enterprise application? “An application that conforms to the Java 2 Platform Enterprise Edition specification“ publib.boulder.ibm.com/infocenter/wasinfo/v5r1/topic/com.ibm.websphere.exp.doc/info/exp/gloss ary.html

4. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is an enterprise application cont’d? An “enterprise application is any software application hosted on a server which simultaneously provides services to a large number of users, typically over a computer network” http://www.theserverside.com/discussions/thread.tss?thread_id=38042

5. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is an enterprise application cont’d? “Enterprise application solve business problems” (Weaver, Mukhar & Crume 2004)

6. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott What is an enterprise application cont’d?  Enterprise applications store, retrieve and manipulate business data (Weaver, Mukhar & Crume 2004) For example, customer invoices, mortgage applications and flight bookings  These applications: Might have multiple user interfaces Handle communication between remote systems Specify the business rules / business logic

7. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications  Traditionally web applications were based on: a two-tier client/server design Proprietary technologies  This approach had implications for (Microsoft 2003): Scalability The integration of other applications Flexibility, and Speed of development

8. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications cont’d  With the introduction of the Microsoft’s Component Object Model (COM), which allows clients to call binary code on a COM server (Platt 2003): Developers could reuse components from third-parties, thus decreasing development time Developers could access operating system functionality such as queuing and transactions, making applications easier to write and more robust

9. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications cont’d  The COM model however had some significant drawbacks, including: The need for a substantial amount of infrastructure to link applications The connecting of applications through an external interface  This resulted in separate implementations of basic data types such as string which had to be converted For example connecting a COM server written in Microsoft Visual Basic with a COM client written in C++

10. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications cont’d  Frameworks have been developed which utilise service-oriented architectures (SOA) and allow (Microsoft 2003): Data, logic, and infrastructure assets to be accessed by routing messages between interfaces Service components to be improved; with changes being carefully controlled Cross-platform integration

11. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications cont’d  Microsoft, for example has implemented service oriented architectures through web services  Web services utilise Internet protocols and standards such as HTTP and XML

12. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Enterprise scale web-based applications cont’d  Two popular application frameworks are: Microsoft.NET Framework Java Enterprise Edition 5 Framework  These frameworks will be discussed in this course

13. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Activity Using your favourite search engine find examples of enterprise-scale web-based applications

14. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Microsoft.NET (Microsoft 2003)  Microsoft.NET is an integral Windows component which supports the building and running of web services; and client- and server-side applications .NET provides: An OOP language neutral environment Enhanced performance, guarantees safe code execution and minimises software deployment A consistent developer experience across apps

15. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Microsoft.NET cont’d  Several different types of applications may be build using.NET including Server applications Web applications Web services Client-side applications  See http://blogs.msdn.com/ericnel/pages/applications- built-for-windows-vista-and-net-framework-3-0.aspx for a list of some real-world applications http://blogs.msdn.com/ericnel/pages/applications- built-for-windows-vista-and-net-framework-3-0.aspx

16. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Microsoft.NET cont’d  The.NET Framework uses a managed code programming model (this will be detailed in the next session)  A wide range of supporting class libraries are provided with the framework, including: Windows Presentation Foundation  For user interfaces, documents and media content

17. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Microsoft.NET cont’d Windows Communication Foundation  Communication infrastructure which utilises the web server architecture Windows Workflow Foundation  Used to create workflow-enabled applications Windows Forms  Form development ASP.NET  Web application development technologies for web application development

18. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Microsoft.NET cont’d ADO.NET  Provides access to data sources

19. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Java Enterprise Edition 5  Java EE is an enterprise framework for component-based multi-tier applications  Java EE applications can handle data from multiple sources and can distribute applications to a variety of clients  Business functions are conducted in the middle tier

20. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Java Enterprise Edition 5  This model provides Scalability Accessibility Manageability  Multi-tier services are divided into: Business and presentation logic Standard system services provided by the framework

21. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Java Enterprise Edition 5  Java Enterprise Edition 5 includes: Java Servlets  Dynamically process request and construct responses; used for service oriented applications (web services) Enterprise JavaBeans (EJB)  Business components that run on the server Java Server Pages (JSP)  Allows creation of static and dynamic web content Java Server Faces (JSF)  Server-side user interface component framework

22. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott.NET vs. Java Enterprise Edition 5  The.NET vs. Java EE is a huge debate with many opinions, including (Silwa 2002) “Weigh the importance of application portability to your company” .NET runs on Windows machines only (for now), while Java Enterprise Edition 5 can easily port business rules and java server pages (JSP)

23. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott.NET vs. Java Enterprise Edition 5 What infrastructure and skills do you have access to?  It is costly to train staff and change infrastructure, for example moving a developer from Cobol to Java could cost US$57,000 per developer (2002 estimate) Examine the complexity of the application .NET tools may be easier to used, Java Enterprise Edition 5 might be better for more complex, mission critical applications

24. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott.NET vs. Java Enterprise Edition 5 Investigate vendor support Look at the costs  Cost of application servers, for example JBOs, WebLogic and WebSphere (for the Java environment)  Also, look at the benefits and flexibility for the future

25. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott.NET vs. Java Enterprise Edition 5  For further comparisons and case studies: http://www.nccaiim.org/Education/Proceedin gs/2004/3-Lyons-ThePlatformWars.pdf http://www.nccaiim.org/Education/Proceedin gs/2004/3-Lyons-ThePlatformWars.pdf

26. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott C# and.NET  In order to run C# and.NET you require: The Microsoft Windows SDK  Microsoft Windows SDK for Server 2003  Microsoft Windows SDK for Server 2008 (latest) Microsoft.NET Framework .NET Framework 2.0 .NET Framework 3.0 .NET Framework 3.5 (latest)

27. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Activity Web install the Microsoft Windows SDK for Server 2008 with the Microsoft.NET Framework 3.5 (over 1GB). http://www.microsoft.com/downloads/details.aspx?familyid=E6E1C3DF- A74F-4207-8586-711EBE331CDC&displaylang=en

28. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott An introduction to C# (Mayo 2008)  This introduction session on C# programming will cover: C# program structure Operators, types, and variables Control statements  Selection If and Switch  Loops While, do, for, foreach

29. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott An introduction to C# cont’d  Some basics C# is like C, C++ and Java C# source files have an extension.cs A Main() method provides the entry point to C# programs  The class with the main method is often called App The Main() method can accept arguments and return a value

30. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott An introduction to C# cont’d  C# is not interpreted  C# is case sensitive  Comments - /* */ and //  All statements end with ;  Write a number of arguments – Console.WriteLine(“{0} {1}”, arg[0], arg[1])  Reading from the console Console.WriteLine(“Hello {0}”, Cosole.ReadLine());

31. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott An introduction to C# cont’d  Compiling a C# program Open the command prompt and locate the program to be compiled Type csc /target:exe program.csc

32. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott An introduction to C# cont’d  See the C# tutorial at http://www.csharp- station.com/Tutorial.aspx http://www.csharp- station.com/Tutorial.aspx

33. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott Conclusion  In this session The.NET and Java Enterprise Edition 5 framework were compared and contrasted Some of the characteristics of enterprise-scale applications were discussed The.NET and the Java Enterprise Edition 5 frameworks were described The student was introduced to the C# programming language

34. © 2008 Dr. Paul Walcott – The University of the West Indies: Cave Hill CampusDr. Paul Walcott References Mayo, J., “The C# Station Tutorial”, 2008. Available online at http://www.csharp- station.com/Tutorial.aspxhttp://www.csharp- station.com/Tutorial.aspx Microsoft Corporation, “A Guide to Building Enterprise Applications on the.NET Framework”, 2003. Available online at http://msdn.microsoft.com/en- us/library/ms954601.aspxhttp://msdn.microsoft.com/en- us/library/ms954601.aspx Platt, D., “Introducing Microsoft.NET”, Third Edition, Microsoft Press, 2003 Silwa, C., “.Net vs. Java: Five Factors to consider”, 2002. Available online at http://www.computerworld.com/developmenttopics/development/story/0,10801,7 1221,00.html http://www.computerworld.com/developmenttopics/development/story/0,10801,7 1221,00.html Sun Microsystems, “The Java EE 5 Tutorial”, 2007. Available online at http://java.sun.com/javaee/5/docs/tutorial/doc/docinfo.html http://java.sun.com/javaee/5/docs/tutorial/doc/docinfo.html