This document provides an overview of J2EE technology and related concepts. It discusses: 1) J2EE as an interface between Java and different web technologies, defining a model for multi-tier web applications. 2) The differences between two-tier and three-tier architectures, with three-tier adopted by J2EE by separating business and data logic. 3) Key J2EE concepts like servlets, JSPs, and the MVC architecture pattern. It also introduces the Struts framework.

1. J2EE TECHONOLOGY
Prepared By:
Govind Singh
Branch: Computer Science
Roll No. : 2010UCS016
Training Location :
Hewlett-Packard Education Services,
Jaipur

2. About HPES
• HP is the largest IT solution and UNIX training
company worldwide.
• HP has been in the education business for over
30 years.
• HP is having more than 400 education centers
worldwide.

3. Content
 Introduction to J2EE
 Servlet
 JSPs
 MVC Architecture
 Introduction to Structs 1.3 Framework

4. Introduction To J2EE
• J2EE is java’s Enterprises Edition that
interfaces and provide platform for different
technologies.
• J2EE defines a model for developing multi-tier,
web based enterprises applications.

5. Two Tier Architecture
• Client can view output in the Browser
• Server having both Web Server and Database
Server.
Client Server

6. Three Tier Architecture
• Business Logics and Database Logics has been
separated.
• It is adopted by J2EE.
client app server server

7. 7
Three Tier architecture(Cont..)
Web Logics
Web Server
(Tomcat, JBoss)
Browser
(IE, Firefox,
Opera)
Desktop
(PC or MAC)
Database
Database
Server
SQLHTTP
HTML tablesvision
touch
Presentation
Layer
Application
Layer
Persistence
Layer

8. Servlet
• Servlets are java codes having HTML inside.
• Servlets are better then CGI
Output
Source Code

9. CGI
Based
Webserver
CGI
Based
Webserver
Request CGI1
Child for CGI1
CGI
Based
Webserver
Servlet Based Webserver
JVM
Request CGI1
Child for CGI1
Request Servlet1
CGI
Based
Webserver
Servlet Based Webserver
JVM
Servlet1
Request CGI1
Child for CGI1
Request CGI2
Request Servlet1
CGI
Based
Webserver
Child for CGI2
Servlet Based Webserver
JVM
Servlet1
Request CGI1
Child for CGI1
Request CGI2
Request Servlet1
Request Servlet2
CGI
Based
Webserver
Child for CGI2
Servlet Based Webserver
JVM
Servlet1
Servlet2
Request CGI1
Child for CGI1
Request CGI2
Request CGI1
Request Servlet1
Request Servlet2
CGI
Based
Webserver
Child for CGI2
Child for CGI1
Servlet Based Webserver
JVM
Servlet1
Servlet2
Request CGI1
Child for CGI1
Request CGI2
Request CGI1
Request Servlet1
Request Servlet2
Request Servlet1
CGI
Based
Webserver
Child for CGI2
Child for CGI1
Servlet Based Webserver
JVM
Servlet1
Servlet2
Request CGI1
Child for CGI1
Servlet vs. CGI

10. Servlet Working
Client Server
Request
Response
HelloServlet.java
helloServlet.class
Read
Generate

11. Servlet
Client
ServerServlet
container
thread
request
response

12. Servlet(cont…)

13. Servlet Working
2
3
1
4
5
6

14. JSP(Java Serve Page)
• JSP is HTML having Java Code inside it.

15. JSP(Java Server Page)
Client Server
Request
Response
Hello.jsp
helloServlet.class
helloServlet.java
Read
Generate
Execute

16. MVC Architecture
• The model is logical backbone of the
application.
• The view (presentation) is responsible to
display the data provided by the model in a
specific format
• The controller handles the model and view
layers to work together

17. MVC Architecture

18. Struts History
• Created in 2000 by Craig R. McClanahan
• Donated to ASF(Apache Software Foundation) in 2000
• Current stable release: 2.3

19. Struts 1.3.x Framework
• Apache Struts is a platform activity.
• Composable Request Processor( for SSLEXT configuration)
• Supports Serialization
• "Extends" attribute
• "isCommitted" Exception Handling
• Postback Actions
• Wildcard ActionConfig properties

20. Struts Directory Structure