Development Platforms Computer Networks Natawut Nupairoj, Ph.D. Department of Computer Engineering Chulalongkorn University

Outline Overview. J2EE Platform. Microsoft.NET Platform. Web Service Platform.

Overview Static vs. dynamic pages. Common Gateway Interface (CGI) External extension (program) for web server. Used mostly to connect to database. Early days C and perl. Counter, guest book, graph generator. Out-of-process model.

Basic CGI Model Problem ? Low performance Must run a new program every time it is being invoked. In-process model – include interpreter inside web server mod_perl. ASP. Plug-in model – separate process (but already started). External AppServer through socket. Web Server Process CGI Program (External) Parameters HTML page

Java Platforms Java-Based Platforms J2SE (Standard Edition) JVM / JRE. Applet and applications. J2ME (Micro Edition) For mobile and wireless equipment. Midlet. J2EE (Enterprise Edition) A set of services. Servlet, JSP, and EJB.

Java Platforms (2)

J2EE Services Java Server Page (JSP). Servlet. Enterprise JavaBean (EJB). Java Connectivity Architecture (JCA). Java Message Service (JMS). Java Management Extension (JMX). Java Naming and Directory Interface (JNDI).

J2EE Architecture

JSP Example

Servlet Example import java.io.*; import javax.servlet.*; import javax.servlet.http.*; public class HelloWorldServlet extends HttpServlet { public void doGet (HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { HTML res.setContentType( "text/html" ); ServletOutputStream out = res.getOutputStream(); out.println( " " ); out.println( " Hello World " ); out.println( " " ); out.println( " Hello World " ); out.println( " Congratulations, your servlet is working! " ); out.println( " " ); }

Microsoft.NET Suite of products Programming Languages C#. ASP.NET. VB.NET. Third parties: NetCOBOL, Visual Perl, Visual Python, etc. Development system. Servers. Common Language Runtime JVM-liked, but supporting multiple languages.

.NET Architecture

Generating Dynamic Pages Model-View-Control Pattern Model – data provider Connect to the database. View – presentation provider Generate HTML page from Model. Control – logic provider Receive a request and control both View and Model.

MVC Pattern Browser Biz Logic (Control) Presentation (View) Web Server Database Logic (Model) Business Logic & PresentationDatabase

Benefits of MVC Pattern Simple to Maintain Separate business, database, and presentation logic. Database access is encapsulated in DB logic. Flexible presentation Template-like system. Simple to support more than one languages.

J2EE in Actions

.NET in Actions

J2EE vs..NET J2EE Multi-Platforms: Unix, Windows, and others. Scalable and high-performance. Complete server-level services: JMS, EJB, JCA, and others..NET Multi-Languages: C#, VB.Net, ASP.Net, and others. Good development tools: Visual Studio.NET. Simple to develop. Built-in supports for XML and Web services. CLR will play a very critical role.

References H. Sheil and M. Monteiro, “Rumble in the jungle: J2EE versus.Net, Part 1”, JavaWorld, June 2002, j2eevsnet_p.html. j2eevsnet_p.html J. Lurie and R. Belanger, “The great debate:.NET vs. J2EE”, Javaworld, March 2002, j2eenet_p.html. j2eenet_p.html jGuru, JavaServer Pages Fundamentals, ro/contents.html. ro/contents.html