Development Platforms

1
Development Platforms

• 2110472 Computer Networks
• Natawut Nupairoj, Ph.D.
• Department of Computer Engineering
• Chulalongkorn University

2
Outline

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

3
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.

4
Basic CGI Model
Web Server Process
CGI Program (External)
Parameters
HTML page

• 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.

5
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.

6
Java Platforms (2)
7
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).

8
J2EE Architecture
9
JSP Example
10
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( "lthtmlgt" )
• out.println( "ltheadgtlttitlegtHello
  Worldlt/titlegtlt/headgt" )
• out.println( "ltbodygt" )
• out.println( "lth1gtHello Worldlt/h1gt" )
• out.println( "ltpgtCongratulations, your servlet
  is working!lt/pgt" )
• out.println( "lt/bodygt" )
• out.println( "lt/htmlgt" )

11
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.

12
.NET Architecture
13
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.

14
MVC Pattern
Business Logic Presentation
Database
Web Server
Biz Logic (Control)
Database Logic (Model)
Browser
Presentation (View)
15
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.

16
J2EE in Actions
17
.NET in Actions
18
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.

19
References

• H. Sheil and M. Monteiro, Rumble in the jungle
  J2EE versus .Net, Part 1, JavaWorld, June 2002,
  http//www.javaworld.com/javaworld/jw-06-2002/jw-0
  628-j2eevsnet_p.html.
• J. Lurie and R. Belanger, The great debate .NET
  vs. J2EE, Javaworld, March 2002,
  http//www.javaworld.com/javaworld/jw-03-2002/jw-0
  308-j2eenet_p.html.
• jGuru, JavaServer Pages Fundamentals,http//devel
  oper.java.sun.com/developer/onlineTraining/JSPIntr
  o/contents.html.