Lecture 19 - Dynamic Web - JAVA - Part 1.ppt

Glassfish, JAVA EE, Servlets, JSP, EJB

• A Java platform comprises the JVM together with supporting
class libraries.
Java 2 Standard Edition (J2SE)
• (1999) provides core libraries for data structures, xml
parsing, security, internationalization, db connectivity, RMI
Java 2 Platform, Enterprise Edition (J2EE)
• provides more class libraries for servlets, JSPs, Enterprise
Java Beans, advanced XML
Java Platform, Enterprise Edition (Java EE)
• When Java Platform 5.0 was released (2004) the ‘2’ was
dropped from these titles.
Java platform

• A Java platform comprises the JVM together with
supporting class libraries.
Java Micro Edition (Java ME)
• comprises the necessary core libraries and tools for
writing Java for embedded systems and other small
footprint platforms, along with some specialised
libraries for specific types of device such as mobile
phones.
Java platform

A Java web application generates interactive web
pages containing various types of markup language
(HTML, XML, and so on) and dynamic content.
It is typically comprised of web components such as:
• JavaServer Pages (JSP)
• Servlets
• JavaBeans
to modify and temporarily store data, interact with
databases and web services, and render content in
response to client requests.
Java Web Application
https://grizzly.dev.java.net/

Java EE (Enterprise Edition) is a widely used
platform containing a set of coordinated
technologies that significantly reduce the cost and
complexity of:
• developing
• deploying and
• managing
multitier, server-centric applications.
Java EE builds upon the Java SE platform and
provides a set of APIs (application programming
interfaces) for developing and running portable, robust,
scalable, reliable and secure server-side applications.
Java EE (Enterprise Edition)
http://netbeans.org/kb/trails/java-ee.html
Java EE 6 is supported
only by the GlassFish
server v3.x.

• The Java EE platform uses a simplified
programming model. XML deployment
descriptors are optional. Instead, a developer
can simply enter the information as
an annotation directly into a Java source file,
and the Java EE server will configure the
component at deployment and runtime
• With annotations, you put the specification
information in your code next to the program
element affected.
Java EE 6 Platform
http://download.oracle.com/javaee/6/tutorial/doc/bnaaw.html

• an architecture for implementing services as
multitier applications that deliver the scalability,
accessibility, and manageability needed by
enterprise-level applications.
• With this structure you can more easily change one
of the tiers without compromising your entire
application.
• Business and presentation logic - to be implemented
by the developer
• Standard system services – to be provided by the
Java EE platform
Java EE application model
http://download.oracle.com/javaee/6/tutorial/doc/bnaaw.html

• Servlets are Java classes that dynamically
process requests and construct responses.
• Server side replacement for CGI
• Extensions to Java enabled web-servers
• Inherently multi-threaded.
• One thread per request.
• Very efficient.
• Platform independent.
Java Servlets

• Servlets run inside a Web Container - the
component of the web server that runs and
interacts with Servlets
• Servlet is running on the server listening for
requests
• When a request comes in, a new thread is
generated by the web container.
How do Servlets work?

Java EE containers
• are the interface between a Java component
and the low-level platform-specific functionality
(i.e. transaction and state management,
multithreading, resource pooling, etc.) that
supports the component.
• provide for the separation of business logic from
resource and lifecycle management.
• this allows developers to focus on writing business logic
rather than writing enterprise infrastructure.
Java EE Containers
http://www.oracle.com/technetwork/java/javaee/javaee-faq-jsp-135209.html#diff
The Java EE platform uses "containers" to simplify development.
http://download.oracle.com/javaee/6/tutorial/doc/bnabo.html

Java EE Containers
When a request comes in:
• a Servlet needs to be instantiated and create a new thread to
handle the request.
• call the Servlet’s doPost()or doGet() method and pass the
HTTP request and HTTP response objects
• get the request and the response to the Servlet
• manage the life, death and resources of the Servlet
* All of the above are the tasks of the web container.

Java EE SERVER
Java EE Containers
From Bodoff et. al. 2005

Client
Web
server
HTML
Server
MySQL
Operating System
PHP
interpreter
Internet
My codes
HTTP
TCP/IP
• Webserver supports HTTP.
Recall: (PHP-MySQL) Server: response
Web
browser
Operating
System

Client
Web
browser
Operating
System
Web server
Servlet
(Java code)
Server
Operating System
Internet
Web
Container
Application
(Java code)
HTTP
TCP/IP
Historically (Java Web App)
Server: response
GET... GET...
It’s the Container that gives
the Servlet the HTTP request
and response, and it’s the
Container that calls the Servlet’s
methods (e.g. doPost() or doGet())
<html>
<head>
</head>
<body>
...
<body>
</html>
<html>
<head>
</head>
<body>
...
<body>
</html>

Client
Web
browser
Operating
System
Web server
Servlet
(Java code)
Server
Operating System
Internet
HTTP
TCP/IP
Historically (Java Web App)
Server: response
GET... GET...
<html>
<head>
</head>
<body>
...
<body>
</html>
<html>
<head>
</head>
<body>
...
<body>
</html>

Client
Web
browser
Operating
System
Web server +
Container
Servlet
(Java code)
Server
Operating System
Internet
HTTP
TCP/IP
(Java Web App) Server: response
GET...
<html>
<head>
</head>
<body>
...
<body>
</html>
Grizzly is now the
HTTP front end of
the application
server

Java Servlets simplify web development by providing
infrastructure for component, communication, and
session management in a web container that is
integrated with a web server.
Java Servlets
http://www.oracle.com/technetwork/java/javaee/javaee-faq-jsp-135209.html#diff
• Writing Servlets is like writing Java codes that place an
HTML page inside a Java class (this is the worst part of
Servlets!)
• (Historically!) requires a deployment descriptor (DD).
This is in the form of an XML file.
• Servlets do not have a main() method.
• Servlets are under the control of another Java
application called a Container

• manage the data flow between the following:
• JavaBeans components are not considered Java EE
components by the Java EE specification.
• JavaBeans components have properties and have get and
set methods for accessing the properties.
JavaBeans
Client/Database Server
application client or applet components running on the
Java EE server
database Server components

Enterprise JavaBeans container handles:
• distributed communication
• threading
• scaling
• transaction management, etc.
has a new packaging! (see figure)
Enterprise JavaBeans (EJB)
http://www.oracle.com/technetwork/java/deepdivejavaee6glassfishv3-jsp-138230.html
New EJB 3.1 Packaging
Older EJB Packaging

• create a simple web application using NetBeans IDE
• deploy it to a server, and
• view its presentation in a browser

• A 3rd party Java Integrated Development Environment
(IDE)
• Comes with Java EE class libraries
• bundled with GlassFish Sever Open Source Edition
• Can deploy servlets, JSPs, and web services
NetBeans
Class libraries for Servlets,
JSPs, Enterprise Java
Beans, advanced XML

A Quick Tour of the IDE (v.6.9)
JSP, Java Bean, User-defined Java Class & Package,
Get Method, User Interface

Sample Project
Index.jsp
NameHandler.java
Main interface, Html with form
Invokes response.jsp through
form action.
response.jsp
Class NameHandler
containing user data
Generates the server’s response
Defines a JavaBean to connect the class NameHandler to
the user’s input via a form text field (name).

Creating a new Web Application
New Project / Java Web

Specify Project Name

GlassFish Server
Web profile

GlassFish
is an open source application server project led
by Sun Microsystems for the Java EE platform. The
proprietary version is called Oracle GlassFish
Enterprise Server. GlassFish is free software
Java Application Server: Glassfish
It uses a derivative of Apache Tomcat as the servlet
container for serving Web content, with an added
component called Grizzly which uses Java NIO for
scalability and speed.
Before the advent of the Java New I/O API (NIO), thread
management issues made it impossible for a server to
scale to thousands of users
https://grizzly.dev.java.net/
Sun is the original creator
of Tomcat
http://java.dzone.com/articles/glassfish-and-tomcat-whats-the

GlassFish is an open source (full) application server project
led by Sun Microsystems for the Java EE platform. The
proprietary version is called Oracle GlassFish Enterprise Server.
GlassFish is free software.
Java Application Server: Glassfish
It uses a derivative of Apache Tomcat as the servlet container
for serving Web content, with an added component called Grizzly
which uses Java NIO for scalability and speed.
On 25 March 2010, soon after the
acquisition of Sun Microsystems, Oracle
issued a Roadmap for versions 3.0.1, 3.1, 3.2
and 4.0 with themes revolving around
clustering, virtualization and integration with
Coherence and other Oracle technologies.
http://en.wikipedia.org/wiki/GlassFish

Historically, if you wanted to get good HTTP performance
from Tomcat you really needed to have an Apache web
server to sit in front of Tomcat which involved more setting
up and extra administrative work.
Since GlassFish v1 (May 2006), Grizzly is the HTTP
frontend of the application server.
It's a 100% Java NIO framework that provides the same
performance as Apache, only it's written in Java and
integrated straight into the application server.
Glassfish vs. Tomcat
Sun is the original creator
of Tomcat
http://java.dzone.com/articles/glassfish-and-tomcat-whats-the
Not a full-
application
server

Other Java web application-capable
Servers
• Blazix from Desiderata Software (1.5
Megabytes, JSP, Servlets and EJBs)
• TomCat from Apache (Approx 6 Megabytes)
• WebLogic from BEA Systems (Approx 40
Megabytes, JSP, Servlets and EJBs)
• WebSphere from IBM (Approx 100 Megabytes,
JSP, Servlets and EJBs)
http://www.jsptut.com/Getfamiliar.jsp

Commercial Deployment
• Oracle GlassFish Server
– delivers a flexible, lightweight and extensible Java EE
6 platform. It provides a small footprint, fully featured
Java EE application server that is completely
supported for commercial deployment and is available
as a standalone offering.
• Oracle WebLogic Server
– designed to run the broader portfolio of Oracle Fusion
Middleware and large-scale enterprise applications.
– industry's most comprehensive Java platform for
developing, deploying, and integrating enterprise
applications.
Oracle provides software support only
for Oracle GlassFish Server, not for
GlassFish Server Open Source Edition
http://docs.sun.com/app/docs/doc/821-1751/gkbtb?l=en&a=view

JSP File

Sample Run

HelloWeb: Directories and Files

Java Package
Right-click Source Packages

Java Package
Add a Java Class, specify Package name
Java Package
• a mechanism for organizing Java classes into namespaces
• can be stored in compressed files called JAR files, allowing classes to
download faster as a group rather than one at a time.

Java Package
Add a Java Class

Java Package
Edit the Java Class
• Declare a String variable inside the
class declaration.
String name;
• Add a constructor to the class:
public NameHandler()
• Add the following line in the
NameHandler() constructor:
name = null;

Generating Getter and Setter Methods
Right-click name field in the Source editor
Selection: Name Field / Refactor / Encapsulate Fields

Notice that Fields' Visibility is by default set to private, and Accessors'
Visibility to public, indicating that the access modifier for class variable
declaration will be specified as private, whereas getter and setter
methods will be generated with public and private modifiers, respectively.

Select the Refactor button.

Notice that the variable
declaration has changed.
• set to private
Get and set functions
with implementation have
been added as well.
• access modifier: public
Results of Refactoring

Adding and Customising
a Form, input text field,
submit button

Invoke the palette: from the menu, select (Window/Palette): or press
Ctrl+Shift+8
expand HTML Forms
Inserting a Form

expand HTML Forms and drag a Form item to a point after the <h1>
tags in the Source Editor.
The Insert Form dialog box displays.
Inserting a Form

Specify the following values:
Click OK.
Specifying an action

An HTML form is automatically added to the index.jsp file.
Source Generated

Drag a Text Input item to a point just before the </form> tag, then
specify the following values:
• Name: name
• Type: text
Adding an Input Text Field

Input Text Field
Source Generated

Drag a Button item to a point just before the </form> tag. Specify the
following values:
• Label: OK
• Type: submit
Click OK. An HTML button is added between the <form> tags.
Adding a Submit Button

Type Enter your name: just before the first <input> tag, then
change the default Hello World! text between the <h1> tags
to Entry Form.
Adding some extra labels, tidying up your code
Right-click within the Source Editor and choose Format
(Alt-Shift-F) to tidy the format of your code.

index.jsp: Source Generated
We would like to
pass this to our
server

In the Projects window, right-click the HelloWeb project node and
choose New > JSP. The New JSP File wizard opens.
Name the file response, and click Finish.
Notice that a response.jsp file node displays in the Projects window
beneath index.jsp, and the new file opens in the Source Editor.
Adding a JSP File

JSP Source File Generated: response.jsp

In the Palette to the right of the Source Editor, expand JSP and drag a
Use Bean item to a point just below the <body> tag in the Source
Editor.
The Insert Use Bean dialog opens.
Specify the values shown in the following figure.
Adding a Use Bean item
The class NameHandler
belongs to the package
we have set earlier

JSP Source File Generated: response.jsp
Notice that the <jsp:useBean> tag is added beneath the <body> tag.

Drag a Set Bean Property item from the Palette to a point just before
the <h1> tag and click OK.
In the <jsp:setProperty> tag that appears, delete the empty value
attribute and edit as follows. Delete the value = "" attribute if the IDE
created it! Otherwise, it overwrites the value for name that you pass in
index.jsp.
Adding a Set Bean property item

Drag a Get Bean Property item from the Palette and drop it after the
comma between the <h1> tags.
Specify the following values in the Insert Get Bean Property dialog:
• Bean Name: mybean
• Property Name: name
Adding a Get Bean property item
Insert a Get Bean Property
item here!

the user input coming from index.jsp becomes a name/value pair that
is passed to the request object.
When you set a property using the <jsp:setProperty> tag, you can
specify the value according to the name of a property contained in the
request object.
JSP Source Code Generated
Therefore, by setting property to name, you can retrieve the value
specified by user input.

Sample Run
User input
Response from
the JSP file

Sample Run
User input Response from
the JSP file
Index.jsp
NameHandler.java
form action.
response.jsp
Class NameHandler
containing user data, get and
set methods

Project
Index.jsp
NameHandler.java
form action.
response.jsp
Class NameHandler
containing user data,
get and set methods
http://java.sun.com/blueprints/code/projectconventions.html

The Java EE specification defines how the web
application can be archived into a web application
archive (WAR)
• WAR files are
– Java archives with a .war extension
– Packaged using the same specification as zip files
– Understood by all Java EE compliant application
servers
• WAR files can be directly deployed in servlet
containers such as Tomcat
Packaging Web Applications

• To make a WAR for your NetBeans project, right click on
the project node and select Build Project.
• The WAR file will be placed in the “dist” sub-directory
of your project folder
NetBeans WAR files

http://netbeans.org/kb/docs/web/quickstart-webapps.html
http://www.oracle.com/technetwork/java/javaee/documentation/index.html
http://netbeans.org/kb/docs/javaee/ecommerce/design.html
E-Commerce Example
http://netbeans.org/kb/docs/javaee/ecommerce/data-model.html#createERDiagram
http://netbeans.org/kb/docs/web/mysql-webapp.html
Simple Database Example
Project
http://download.oracle.com/javaee/6/tutorial/doc/
Java EE 6
NetBeans
http://java.sun.com/blueprints/code/projectconventions.html
Recommended Directory Structure for Projects

http://dot.netbeans.org:8080/AffableBean/

Model-View-Controller Paradigm

Lecture 19 - Dynamic Web - JAVA - Part 1.ppt

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Editor's Notes