1. Presentation 27: Comparison of technologies

2. Ingeniørhøjskolen i Århus Slide 2 af 11 Goals of this lesson After this 1x35 lessons you will have –Discussed the different Middleware technologies –And be in a position to better decide when to use which technology

3. Ingeniørhøjskolen i Århus Slide 3 af 11 Outline Discussion in plenum –Pro’s and Con’s of each Middleware technology –When to use which? –Important that you form your own opinion –Do NOT use mine After discussion –7 scenarios – when to use? You decide!

4. Ingeniørhøjskolen i Århus Slide 4 af 11 Discussion Java RMI – Pro’s & Con’s CORBA – Pro’s & Con’s.NET Remoting – Pro’s & Con’s Web Services (SOAP) – Pro’s & Con’s DCOM - Pro’s & Con’s

5. Ingeniørhøjskolen i Århus Slide 5 af 11 7 scenarios In the following I present 7 scenarios It is up to you to decide which technology to use – and we may debate it during the presentation I will come up with suggetions – but they may not be better than yours!

6. Ingeniørhøjskolen i Århus Slide 6 af 11 Scenario 1 Server program to be written in Java and run on UNIX servers Clients to run on primarely Windows machines – written in C++ Clients communicate via LAN internally in the company Which technology? –CORBA seems the most appropriate –SOAP could be considered – BUT IS LIGHT-WEIGHT COMPARED TO CORBA

7. Ingeniørhøjskolen i Århus Slide 7 af 11 Scenario 2 Need for exposing a few data from an exsisting legacy application running on a UNIX platform which was written in Java Data is to be delivered to several client programs running on different operating systems: Mac, Windows and Linux, and written in different programming languages – using uncontrolled firewalls in different locations Many different small software companys are the targets, skills unknown Which technology? –SOAP seems the most appropriate –CORBA could be considered

8. Ingeniørhøjskolen i Århus Slide 8 af 11 Scenario 3 A system is being designed: –Server: Java program running on a UNIX server –Client: Java program running on Windows and LINUX –Client option: possible client J2ME on mobile phones Which technology? –Java RMI seems the most appropriate No support for RMI on J2ME yet –CORBA is possible – opening up for other clients No CORBA support on J2ME yet –SOAP support for J2ME – kSOAP and WingFoot … Would support other types of client in the future

9. Ingeniørhøjskolen i Århus Slide 9 af 11 Scenario 4 A system is being designed: –Server running on a LINUX platform – Java language –Client – Windows XP PC written in C++ –Client – Windows CE Smartphone edition (C++) –Client – Symbian J2ME mobile phone –Client – LIAB (Linux in a Box) – optional –Problem: communicating via GSM – high latency Which technology: –Maybe CORBA sounds best, but SOAP is the only supported by the Symbian J2ME (WingFoot, kSOAP) –SOAP Works on the.NET CF for SmartPhone!

10. Ingeniørhøjskolen i Århus Slide 10 af 11 Scenario 5 A system is being designed: –Server running Windows 2000 written in C++ Implementing accounting, employee records, planning scedules etc. –Planned clients include: An accounting program written in Delphi A phonebook program written in ASP.NET (VB Script) An employee update & planning program written in C# Which technology? –COM is obvious for the pure Microsoft platform –.NET Remoting is possible –CORBA is possible –SOAP is possible

11. Ingeniørhøjskolen i Århus Slide 11 af 11 Scenario 6 A small company has just made a killer application offering other developers access to: –Searching the Web –Sending and recieving mails and SMS messages –All for free – using sponsporship as a sole income –They want other companys to incoporate the functions they have into their own programs – and devices All kinds of technologies possible here!!! Which technology? –SOAP is obviously suited for this. Every small company can integrate, and no trouble with firewalls!

12. Ingeniørhøjskolen i Århus Slide 12 af 11 Scenario 7 A company has just made a networked temperature surveillance unit. Main core is a microprocessor with a socket and HTTP stack – and 16 KB of available memory The unit is to plug-in into any conceivable type of data- collection system – amongst others ethernet-based PC- servers First customer is using an existing CORBA-based PC server for management What advice on middleware would you give them? –simple socket programming, TCP/UD, seems appropriate – no room for middleware, no need for middleware