Introduction To Java Beans
J2EE specification defines the
structure of a J2EE application. According to the specification J2EE
application consists of two components, web component and the
Web component consists of all
the programs and the files used to provide the user interface and
these may contain JSP, Servlets, images, html files etc. These files
are archived into .war file and deployed on the web server.
Enterprise Bean consists of all
the program necessary to provide the business to the application.
These files are archived into .jar file and are deployed on the
application server such as WebLogic 6.0.
You can deploy the web component
and the ejb components separately on the web server and the
application server respectively. J2EE specification also provide a way
to package these files into one archive .ear file and then deploy on
Writing and deploying
the web component
In this section we are going to
describe you how to write and deploy the web component on the WebLogic
6.0 web server.
Web component follows the standard
directory structure defined in the J2EE specification.
Structure of Web Component
index.htm, JSP, Images etc..
Root directory of the
web archive ('.war' file) contains all the html, jsp, images files and
the additional directories containing these files. In the root
directory there is a special directory 'Web-inf' which contains
the web deployment descriptor (web.xml), classes and the lib
To download the code
for this lesson click here. To deploy this
web component download the code and then extract it in you favorite
directory. One directory will be created with the name of lesson1, go
to the leson1 directory and to create the war file issue the following
command from dos prompt:
jar cf lesson1.war *
component file with the name of lesson1.war will be created. You can
deploy it to the WebLogic 6.0 server using console. After deploying it
using the WebLogic 6.0's console type http://localhost:7001/lesson1/
to view. Server will serve index.jsp to your browser.
let's see the web.xml file which describes the content of the web
component. Here is the content of web.xml file.
|<?xml version="1.0" encoding="ISO-8859-1"?>
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
web.xml file start with xml declaration
and after the document type declaration <web-app> tag starts.
All the information regarding the content of the .war file are written
between <web-app> and </web-app> tags in the xml format.
the first lesson we are setting index.jsp as our welcome page and the
following lines of the web.xml file is used to accomplish this.
following code sets the session time:
To learn more
about writing the web.xml file and deploying the web application on
WebLogic 6.0 please visit:
the next lesson we will write stateless session bean and then deploy
on the WebLogic 6.0 Server.