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Methodologies in Information Systems
Development
Tutorial:
Server-Side Web Applications with
Java, JSP and Tomcat
Eran Toch
December 2004
Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
2
Web Application vs. Web Site
Web Site
Web Application
Web
Service
Data
Mainframe
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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The Difference – cont’d
Web sites are
– Static
– File based
– May include client’s JavaScript code
• Web Applications are
–
–
–
–
–
Dynamic (output depend on input)
Database based
Multi-layered
Session dependent (most of the times)
Personalized (some of the times)
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Java Web Application Architecture
Browser
HTTP / HTML
Application Server
Servlet
Java Classes
/ EJB
JSP
DB / ERP /
Legacy
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
6
Tomcat Installation
• Go to: http://jakarta.apache.org/tomcat/
• Download the latest version (currently 5.5.4)
by going to: Downloads -> Binaries -> Tomcat
5.5.4.
– For Windows, download the exe version – with a
Windows setup. The direct link:
http://apache.fresh.co.il/jakarta/tomcat5/v5.5.4/bin/jakarta-tomcat-5.5.4.exe
– For Linux, read the setup manual:
http://jakarta.apache.org/tomcat/tomcat-5.5doc/setup.html
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Tomcat and Java 5
• Please note that Tomcat v. 5.5.4 requires
J2SE 1.5 (also known as J2SE 5) or above.
• If you want to use J2SE 1.4, download
Tomcat 5.0.+
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
8
Tomcat Installation – cont’d
If you want Tomcat to
startup every time the
computer is rebooted,
check the “service” option.
If you wish to use Tomcat
for only for development,
it’s best to leave the
service option unchecked.
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
9
Tomcat Installation - Port
You can configure the port
that Tomcat will be using. If
you want it to be available
publicly (behind firewalls
etc), change the default port
to 80. Otherwise, leave it as
it is (880). You can always
change it later, in the
[TOMCAT_HOME]/conf/serv
er.xml configuration file.
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
10
Running Tomcat
• Start Tomcat by running Tomcat monitor
(Start Menu -> Apache Tomcat -> Monitor
Tomcat), and click on Start.
– Point your browser to:
http://localhost:8080. If
Tomcat works, you should
see something like this
– If not, check out the logs
(C:\[TOMCAT_HOME]\logs\s
tdout) and see what went
wrong.
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
11
Managing Tomcat
• Go to the management console by clicking
on the “management” link in the Tomcat root
homepage, or directly by going to:
http://localhost:8080/manager/html.
• The default username is “admin”, and the
default password is ””
• You can change it by changing the
[TOMCAT_HOME]\conf\tomcat-users.xml.
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
12
Managing Tomcat Console
Start, stop, restart
and un-deploy
applications
Web Application
management
Number of
current
sessions
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
14
Building A Web Application
• Build the following folder structure under
[TOMCAT-HOME]\webapps
Tomcat-home
webapps
This is the
hard way…
There are
better
common
conf
...
phones
WEB-INF
jsp
lib
classes
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
15
Creating JSP Project in Eclipse
1. Open a project
for the JSP
pages
2. Choose the type
“Simple project”
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Creating JSP Project – cont’d
• Choose the path
to the jsp folder
• Click “Finish”
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Creating Java Classes Project
• Create a new
project
• Choose “Java
Project”
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Creating Java Project – cont’d
• Choose the path
to the WEBINF/classes
folder
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Creating Java Project – cont’d
• Make sure the
output build path
is in the WEB-INF
classes folder
• Necessary
libraries could be
added now
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Better ways
• Download MyEclipse IDE extension from:
http://www.myeclipseide.com/
• Download Lomboz plugin for Eclipse at:
http://www.objectlearn.com/index.jsp
• Both of these plugins will give you:
– Easier deployment of projects
– JSP debugging
– JSP error detection (important!)
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
21
Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
22
Our “Phones” Application
• Simple application that displays phone
records from the database
• (stupid, shameless) Architecture:
select_entry.jsp
display_phone.jsp
PhoneEntry.java
Database
DBConnector.java
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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PhoneEntry.java
package edu.technion.methodologies.phones;
public class PhoneEntry {
private int id = 0;
private String name;
private String phone;
private String email;
public void load(int id)
{
DBConnector.loadPhone(id, this);
}
public void save() {
if (id == 0)
{
id = DBConnector.insertPhone(this);
}
else
{
DBConnector.updatePhone(id, this);
}
}
//getters and setters…
}
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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DBConnector.java
• See the advanced Java tutorial…
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
25
Writing Scriplets in JSP
• Write HTML as normal
• Dynamic parts between <%
• Eg
%>
<HTML>
<BODY> Hello! The time is now <%= new java.util.Date() %>
</BODY>
</HTML>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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JSP Scripting Elements
• Expressions <%= expression %>
• evaluated and inserted into the output
• Scriptlets <% code %>
• inserted into the servlet's service method
• Declarations <%! code %>
• inserted into the body of the servlet class, outside of
any existing methods
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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JSP Directives
• There are two main types of directive:
– page
• lets you do things like import classes, customize the
servlet superclass etc
– Include
• lets you insert a file into the servlet class at the time the
JSP file is translated into a servlet.
• <%@ directive attribute="value" %>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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select_entry.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
HTML
<TITLE>Phones Application</TITLE>
Header
</HEAD>
<BODY>
<form action="display_phone.jsp" method="post">
<table border=0>
<tr>
<td>ID: </td>
<td><input type="text" name="id"></td>
</tr>
<tr>
<td>&nbsp;</td>
<td><input type="submit"></td>
</tr>
</table>
</form>
</BODY>
</HTML>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
HTML form
Nested HTML
table structure
HTML text input
29
select_entry.jsp – the HTML output
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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display_phone.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<%@page import="edu.technion.methodologies.phones.*" %>
<HTML>
<HEAD>
Importing
<TITLE>Phone Entry</TITLE>
libraries
</HEAD>
<BODY>
<%
String idParam = request.getParameter("id");
int id = 0;
if (idParam != null){
id = Integer.parseInt(idParam);
}
PhoneEntry phoneEntry = new PhoneEntry();
phoneEntry.load(id);
%>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
Handling the
request
Creating the
JavaBean
31
display_phone.jsp – cont’d
<table border=0>
<tr>
<td>Name:</td>
<td><b><%= phoneEntry.getName() %></b></td>
</tr>
<tr>
<td>Phone:</td>
<td><%= phoneEntry.getPhone() %></td>
</tr>
<tr>
<td>Email:</td>
<td><%= phoneEntry.getEmail() %></td>
</tr>
</table>
</BODY>
</HTML>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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display_phone.jsp – the HTML Output
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
33
Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
34
JSP Include
• Inserting elements into the JSP page in
complication time
Included JSP file
<table border="0" width="100%" cellpadding="4">
<tr bgcolor="99CCFF">
<td><a href="select_entry.jsp">home</a></td>
</tr>
</table>
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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JSP Include – cont’d
We add the include declarative into display_phone.jsp
…
<BODY>
<%@include file="header.jsp"%>
<%
…
And we get:
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
36
Session and Application Objects
• A session is an object associated with a visitor.
• Data can be put in the session and retrieved from it
//Setting an object within the session
session.setAttribute("last_searched_id", new Integer(id));
//Getting an object from the session
Integer lastID = (Integer)session.getAttribute("last_searched_id");
out.println(lastID);
• Sessions are timed-out – the default is ~25 minutes
• The application object is accessed similarly, but is
unique and global for the web application
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Advanced Issues
• Servlets – have many advantages over JSP
– Inheritance
– Class structure
• Tag libraries
• Enterprise Java Beans
• J2EE Frameworks (WebLogic, Web Sphere,
JBoss)
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
38
Agenda
•
•
•
•
Introduction and architecture
Installing Tomcat
Building a Web Application (through Eclipse)
The Phones Web Application
– Writing JavaBeans
– Writing JSPs
• Includes, session and application
• Model 2 Architecture
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
39
Model 2 Architecture
• recommended approach for designing
medium- and large-sized Web applications
• An implementation of the Model-ViewController (MVC) pattern
• Applications have 3 layers
– Model: containing all data and operations
» JSP classes or beans
– View: creating various presentations
» JSP – focus on static data
– Controller: receiving requests, updating the model,
and delegating to views
» servlet
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Model 2 Architecture – cont’d
VIEW
CONTROLLER
MODEL
.jsp
servlet
classes
Database
.jsp
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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Struts
• Struts is an open source framework created
within the Jakarta project by the Apache
Software Foundation
• Supports Model-View-Controller (MVC)
design pattern
• http://struts.apache.org/
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
Methodologies in Information System Development
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References
• Core Servlets and JavaServer Pages, Vol. 1: Core
Technologies, Second Edition, by Marty Hall, Larry
Brown
• Sun’s JSP Tutorial:
http://java.sun.com/j2ee/tutorial/1_3fcs/doc/JSPIntro.html
• JavaBeans Tutorial:
http://java.sun.com/j2ee/tutorial/1_3fcs/doc/JSPBeans.html
• A set of advanced (and untidy) tutorials:
http://www.coreservlets.com/
Server-Side Web Applications with Java, JSP and Tomcat – Eran Toch
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