The document provides an overview of Java 2 Platform Enterprise Edition (J2EE) architecture. It discusses the key components and features of J2EE, including how it addresses limitations of two-tier architectures. The main J2EE components are Servlets, Java Server Pages (JSP), and Enterprise JavaBeans (EJB). Servlets and JSPs make up the presentation logic tier, while EJBs comprise the application logic tier. The document also provides examples of a simple Servlet and JSP code.

1. SARVAJANIK COLLEGE OF ENGINEERING AND TECHNOLOGY
COMPUTER ENGINEERING DEPARTMENT
B. E. III, CO – M, 6th Semester
ALA Presentation
On
“J2EE”
Subject Name : Advanced Java (2160707)
Prepared and Presented by (Group No. : 18)
SUVRA KANTI MANDAL(160420107065)
DITIRO RANKO(160420107068)
SYADA SARA ENAM ROJA(160420107069)
Guided by:
Prof. Bhavesh Patel
Prof. Vandana Joshi

2. Presentation Overview
• Introduction to J2EE
• 2-tier Architecture
• J2EE
• J2EE features
• J2EE Components
• J2EE Application Model
• Servlet
• JSP
2

3. Past History
• Initially two tier architecture (client server applications)
• Client is responsible for data access applying business logic a
nd presentation of data
• Only service provided by Server was that of database server.
3

4. Two Tier Application Architecture
Client Server
4

5. Two Tier Application Architecture
• Drawbacks
- Easy to deploy but difficult to
enhance or upgrade.
- It makes reuse of business and
presentation logic difficult
- Not scalable and not suited for
internet
5

6. Java 2 Platform Enterprise Editio
n (J2EE)
J2EE is an architecture for implementing enterprise class a
pplications using Java and Internet Technology
- Solves problems of two tier architecture
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7. J2EE Tiers
• Client Presentation
HTML or Java applets deployed in Browser
XML documentations transmitted through HTTP
Java clients running in Client Java Virtual Machine (JVM)
• Presentation Logic
Servlets or Java Server Pages running in web server
• Application Logic
Enterprise JavaBeans running in Server
7

8. J2EE
• To develop n tier application
• It supports the development of a variety of application types-
 Small client server systems
 Systems running on Intranets
 Systems on large scale internet e-commerce site
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9. J2EE Features
• Component based model
• Container provided services
• Highly Scalable
• Simplified Architecture
• Flexible security model
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10. J2EE Components
10

11. J2EE Components & Services
• Primary technologies
- Servlets
- Java Server Pages (JSP)
- Enterprise JavaBeans (EJB)
• Standard services & supporting technologies
- Java database connectivity(JDBC) data access API
- Remote Method Invocations (RMI)
- Extensible Markup Languages(XML)
- JavaIDL
- JavaMail
11

12. J2EE Application Model
12

13. J2EE Application Model
• Browser is able to process HTML and applets pages.
• It forwards requests to the web server, which has JSPs and Se
rvlets
• Servlets and JSPs may access EJB server.
• Java Standalone runs on java client, which access EJB server
using RMI.
13

14. States and Persistence
• Session beans can be
• Stateless- belong to client for duration of a method call
• Stateful- belong to client for duration of client conversation
• Entity beans can have
• Bean-managed persistence- The developer writes SQL code to retrieve
, store and update database
• Container managed persistence- The developer provide database mapp
ing information that allows the container to manage persistence
14

15. Overview of Servlets
• Are container managed web components
• Replace Common Gateway Interface(CGI) or Active Server
Pages (ASP)
• Generate dynamic response to requests from web based client
s
• Synchronize multiple concurrent client request
• Serve as client proxies
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16. Servlet Operation
• Server is Java program that ru
ns as separate thread inside ser
vlet container.
• Servlet container is part of we
b server
• It interact with web client usin
g response request paradigm
16

17. Sample Servlet
import java.io.*; //Apache Tomcat sample code
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloWorld extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, Servlet
Exception
{
response.setContentType("text/html");
PrintWriter out = response.getWriter(); out.println("<html>"); out.println("<body>");
out.println("<head>");
out.println("<title>Hello World!</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Hello World!</h1>");
out.println("</body>");
out.println("</html>");
}
}
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18. Java Server Pages (JSP)
• Text based documents describe how to process a request and
create a response
• Contains HTML or XML and other JSP elements defined by
JSP specification.
• Are Installed on web server
• are web components that sits on top of java servlet mode.
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19. JSPAdvantages
• Performance
• Runtime characteristics of servlets
• Automatic recompilation of modified pages
• Server side processing
• Programming
• Emphasize use of reusable components
• Write Once , Run Anywhere properties
• Extensible through custom tag libraries
• Provides front end access mechanism to EJBs
19

20. Sample JSP
<html> <!- Apache Tomcat Samples ->
<!-- Copyright (c) 1999 The Apache Software Foundation. All rights reserved.-->
<body bgcolor="white">
<jsp:useBean id='clock' scope='page' class='dates.JspCalendar' type="dates.JspCalendar" />
<font size=4><ul>
<li> Day of month: is <jsp:getProperty name="clock" property="dayOfMonth"/>
<li> Year: is <jsp:getProperty name="clock" property="year"/>
<li> Month: is <jsp:getProperty name="clock" property="month"/>
<li> Time: is <jsp:getProperty name="clock" property="time"/>
<li> Date: is <jsp:getProperty name="clock" property="date"/>
<li> Day: is <jsp:getProperty name="clock" property="day"/>
<li> Day Of Year: is <jsp:getProperty name="clock" property="dayOfYear"/>
<li> Week Of Year: is <jsp:getProperty name="clock" property="weekOfYear"/>
<li> era: is <jsp:getProperty name="clock" property="era"/>
<li> DST Offset: is <jsp:getProperty name="clock" property="DSTOffset"/>
<li> Zone Offset: is <jsp:getProperty name="clock" property="zoneOffset"/>
</ul>
</font>
</body>
</html>
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21. J2EE Servers
•Application Server
• As of Sept ’01 - MetaGroup Survey by sales $$
• BEA Weblogic - 37%
• IBM Websphere – 22%
• Oracle – 11%
• Iplanet – 5%
• Other- 12%
• Open-source
• Jboss – www.jboss.org
• Sun’s listing of J2EE compatible servers - http://java.sun.com/j2
ee/compatibility.html
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22. Thank You…