Lecture 19 dynamic web - java - part 1

Glassfish, JAVA EE, Servlets, JSP, EJB

Java platform
• A Java platform comprises the JVM together with supporting
class libraries.
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.
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.
phones

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

Java EE (Enterprise Edition)
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

Java EE 6 is supported
only by the GlassFish
server v3.x.

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.
http://netbeans.org/kb/trails/java-ee.html

Java EE 6 Platform
• The Java EE platform uses a simplified
programming model. XML deployment
descriptors are optional. Instead, a developer
optional
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
annotations
information in your code next to the program
element affected.
http://download.oracle.com/javaee/6/tutorial/doc/bnaaw.html

Java EE application model
• 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
http://download.oracle.com/javaee/6/tutorial/doc/bnaaw.html

Java Servlets
• 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.
multi-threaded
• One thread per request.
• Very efficient.
• Platform independent.

How do Servlets work?
• 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.
container

Java EE Containers
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.
infrastructure
The Java EE platform uses "containers" to simplify development.
containers
http://download.oracle.com/javaee/6/tutorial/doc/bnabo.html

http://www.oracle.com/technetwork/java/javaee/javaee-faq-jsp-135209.html#diff

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
doPost()
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.
container

Java EE Containers
Java EE SERVER

From Bodoff et. al. 2005

Recall: (PHP-MySQL) Server: response
• Webserver supports HTTP.

Server
Web
server

Client

HTTP

My codes
HTML

MySQL

Operating System

Web
browser

TCP/IP

Operating
System

Internet

PHP
interpreter

Historically (Java Web App)
Server: response


Server
GET...
Web server

Client
Web
browser

HTTP

GET...

Web
Container
Application
<html>
<head>
</head>
<body>
...
<body>
</html>

(Java code)

<html>
<head>
</head>
<body>
...
<body>
</html>

Servlet
(Java code)

Operating System

TCP/IP

Operating
System

Internet

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())

Historically (Java Web App)
Server: response

Server
GET...

Web server

GET...

<html>
<head>
</head>
<body>
...
<body>
</html>

Servlet

Client
Web
browser

HTTP

(Java code)
<html>
<head>
</head>
<body>
...
<body>
</html>

Operating System

TCP/IP

Operating
System

Internet


(Java Web App) Server: response

Server
GET...

Grizzly is now the
HTTP front end of
the application
server

Web server
+ Container

<html>
<head>
</head>
<body>
...
<body>
</html>

Servlet
HTTP

Client

(Java code)

Operating System

Web
browser

TCP/IP

Operating
System

Internet


Java Servlets
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.
server
• 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.
file
• Servlets do not have a main() method.
• Servlets are under the control of another Java
application called a Container
http://www.oracle.com/technetwork/java/javaee/javaee-faq-jsp-135209.html#diff

JavaBeans
• manage the data flow between the following:
Client/Database

Server

application client or applet

components running on the
Java EE server

database

Server components

• 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.
properties

Enterprise JavaBeans (EJB)
Enterprise JavaBeans container handles:
• distributed communication
• threading
• scaling
• transaction management, etc.
has a new packaging! (see figure)

New EJB 3.1 Packaging
Older EJB Packaging

http://www.oracle.com/technetwork/java/deepdivejavaee6glassfishv3-jsp-138230.html

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

NetBeans
• A 3rd party Java Integrated Development Environment
(IDE)
Class libraries for Servlets,
JSPs, Enterprise Java
Beans, advanced XML

• Comes with Java EE class libraries
• bundled with GlassFish Sever Open Source Edition
• Can deploy servlets, JSPs, and web services

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

Main interface, Html with form
Invokes response.jsp through
form action.

NameHandler.java
Class NameHandler
containing user data

response.jsp

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

Java Application Server: Glassfish
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
Sun is the original creator
of Tomcat

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.
https://grizzly.dev.java.net/

http://java.dzone.com/articles/glassfish-and-tomcat-whats-the

Before the advent of the Java New I/O API (NIO), thread
NIO
management issues made it impossible for a server to
scale to thousands of users

Java Application Server: Glassfish
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.
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
Microsystems
Roadmap for versions 3.0.1, 3.1, 3.2 and 4.0
with themes revolving around clustering,
clustering
virtualization and integration with
Coherence and other Oracle technologies.
http://en.wikipedia.org/wiki/GlassFish

Glassfish vs. Tomcat
Not a fullapplication
server

Sun is the original creator
of Tomcat

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.
http://java.dzone.com/articles/glassfish-and-tomcat-whats-the

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
• WebSphere from IBM (Approx 100

http://www.jsptut.com/Getfamiliar.jsp

Commercial Deployment
• Oracle GlassFish Server

Oracle provides software support only
for Oracle GlassFish Server, not for
GlassFish Server Open Source Edition

– 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.
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'
private
Visibility to public, indicating that the access modifier for class variable
declaration will be specified as private, whereas getter and setter
private
methods will be generated with public and private modifiers, respectively.


Select the Refactor button.

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

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

Inserting a Form
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.

Specifying an action
Specify the following values:

Click OK.

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

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

Source Generated
Input Text Field

Adding a Submit Button
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 some extra labels, tidying up your code
Type Enter your name: just before the first <input> tag, then
change the default Hello World! text between the <h1> tags
to Entry Form.
Form
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

Adding a JSP File
In the Projects window, right-click the HelloWeb project node and
choose New > JSP. The New JSP File wizard opens.
JSP
Name the file response, and click Finish.
response
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.
Editor

JSP Source File Generated: response.jsp

Adding a Use Bean item
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.

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.

Adding a Set Bean property item
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.
index.jsp

Adding a Get 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

Insert a Get Bean Property
item here!

JSP Source Code Generated
the user input coming from index.jsp becomes a name/value pair that
is passed to the request object.
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.
object

Therefore, by setting property to name, you can retrieve the value
name
specified by user input.
input

Sample Run

User input

Response from
the JSP file

Sample Run
Index.jsp

form action.

User input
NameHandler.java

response.jsp

Response from
the JSP file

Class NameHandler
containing user data, get and
set methods


Project
Index.jsp

form action.

NameHandler.java
Class NameHandler
containing user data,
get and set methods

http://java.sun.com/blueprints/code/projectconventions.html

response.jsp


Packaging Web Applications
The Java EE specification defines how the web
application can be archived into a web application
archive (WAR)
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

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

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

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

Model-View-Controller Paradigm

Lecture 19 dynamic web - java - part 1

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