ebusiness Application Development

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e-business Application Development
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J2EE vs .Net
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Benefits of J2EE

• Simplified architecture and development
• Variety of standard services, components, and
  clients
• Choices of tools
• Portability
• Integration with existing information systems
• Separation of Responsibilities
• Scalability
• Flexible security model

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J2EE Technologies Summary
J2EE 1.3 Required Standard Extension APIs
API
Applet
Application Client
Web
EJB
JDBC 2.0
N
Y
Y
Y
JTA 1.0
N
N
Y
Y
JNDI 1.2
N
Y
Y
Y
Servlet 2.3
N
N
Y
N
JSP 1.2
N
N
Y
N
EJB 2.0
N
Y1
Y2
Y
RMI-IIOP 1.0
N
Y
Y
Y
JMS 1.0x
N
Y
Y
Y
JavaMail 1.2
N
N
Y
Y
JAF 1.0x
N
N
Y
Y
1 Application clients can only make use of the
enterprise bean client APIs. 2 Servlets and JSP
pages can only make use of the enterprise bean
client APIs.
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Server Side Component - JSP

• HTML document
• Embedded JSP specific tags
• Inline Java Code
• On the server, JSP Page is parsed and compiled
  into a Java Servlet
• WebSphere 5.0 fully supports JSP1.2

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Server-Side Components - Servlets

• Servlets are Java classes that allow application
  logic to be embedded in HTTP request-response
  process.
• J2EE 1.3 requires
• Servlet 2.3 specification

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J2EE Services JDBC

• Provides database-independent connectivity to a
  variety of data stores
• J2EE 1.2 specifies
• JDBC 2.0 Core APIs - Basic database services
• JDBC 2.0 Extension APIs - Advanced functionality
• Connection Pooling
• Transactional capabilities
• Functionality provided by a combination of
  WebSphere and a compliant JDBC driver

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Application Servers

• Application Servers
• Work with Web server to manage browser and Java
  based client sessions
• Support server-side business logic
  (Servlets/JavaServer Pages/EJBs)
• Connect to back end computing resources for data
  and transaction processing
• Application server benefits
• Simplify development and deployment of
  web-enabled e-business applications
• Support connections to legacy data and
  applications
• Deliver a set of application deployment and
  management tools

Application Serving
Transaction Serving
Client
Page Serving
Business Applications
App Server
Web Server
Active Business Rules
User Interface
Transactions
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Model-View-Controller architecture

• Reduce the programming effort required to build
  and maintain systems
• Separate the application into 3 distinct layers
• Controller - application flow
• Model - business logic
• View - the output
• Models, Controllers, and the views are treated as
  separate entities
• Changes can be made independently
• Different people/skills can work independently

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WebSphere Application Server
/JSP
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Software

• HTTP Servers
• Apache HTTP Server (Open Source)
• IBM HTTP Server powered by Apache
• Many others
• Some Application Servers
• Jakata Apache (Open Source)
• Tomcat
• IBM WebSphere Application Server
• BEA Weblogic
• Sun iPlanet
• And more
• Comparable MS support
• IIS (Internet Information Services)

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WebSphere Application Server - Express

• An offering from IBM that contains
• WebSphere Application Server
• WebSphere Studio Site Developer
• IBM Agent Controller
• Tools to build and deploy J2EE compliant
  applications

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WebSphere Application Server Express
ExpressApplication Server
Site Developer
Webprojects
Develop
Agent Controller
Applicationserver- JSPs- Servlets
deploy
ExpressTestEnvironment
Web server-HTML-images
WebClient
Data Access -DB2 -Oracle -SQL Server
-Cloudscape
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Perspectives

• A group of related views and editors is called a
  perspective
• Configurable

• There is a perspective for each of the different
  roles in a development life cycle (some roles
  overlap)
• Open different perspectives by
• PerspectivegtOpengtOther
• Selecting Open Perspective Button
• To switch between perspectives use shortcut bar

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Perspective/Project, What's the difference?

• Perspectives are different ways of looking at the
  same project

Projects - a grouping of resources
Perspectives-multiple views of assets in
workbench providing tools to help with task
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Views

• Perspectives are made up of views
• Display a view by selecting Perspective gt Show
  Views

• Views support
• Editors
• Provide alternative presentations or navigation
  of the information
• A view might appear by itself, or stacked with
  other views in a tabbed notebook
• Views can be floated by Selecting the blue bar at
  the top of the Tasks view and drag it on to the
  desktop.

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Web Application

• Defined in J2EE and Java servlet specification
• Standardized format which is compatible between
  multiple vendors
• Contains
• JavaServer Pages
• Servlets
• Applets
• HTML and XML files
• Meta information to connect elements
• Deployment descriptor

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J2EE Deployment Descriptor (DD)

• XML-based files describing the environment for
  modules and its components
• Each module and ear file has a deployment
  descriptor
• Can be automatically created and verified by
  WebSphere's deployment tool
• Application Assembly Tool (AAT)
• Can be manually created or edited

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Running the Application

• Need to create an application server
• Site Developer will create one for you
• HTTP Server
• Application Server

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WebSphere Application Server Express
ExpressApplication Server
Site Developer
Webprojects
Develop
Agent Controller
Applicationserver- JSPs- Servlets
deploy
ExpressTestEnvironment
Web server-HTML-images
WebClient
Data Access -DB2 -Oracle -SQL Server
-Cloudscape
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Web Pages

• Static
• Constant information
• Can only be changed by changing the html page
• Dynamic
• Information changes
• Database access
• May be customized for individual end user
• Personalization

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Creating an HTML Page
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HTML Editor
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Framesets
header.html
toggle
menu.html
main.html
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Frameset source
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Setting attributes
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Using tables
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The completed table
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Adding Links
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Cascading Style Sheet

• A file that defines a hierarchical set of style
  rules that the creator of an HTML or XML file
  uses in order to control how that page is
  rendered in a browser or viewer, or how it is
  printed. 
• A CSS includes a defined order of precedence to
  address cases when the definitions of any style
  element in a document conflict. 

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Cascading Style Sheets
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Set Style Properties
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WebArt Designer
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Common Database Models

• Relational
• Stores data in a database consisting of one or
  more tables of rows and columns
• Object
• Combine the elements of object orientation and
  object-oriented programming languages with
  database capabilities
• Support additional data types (complex types)

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Relational Model Concepts
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SQL

• Structured Query Language
• Provides a standard language to access relational
  databases
• Works with most common database systems
• Microsoft Access, IBM DB2, Oracle, Informix, MS
  SQL Server
• SQL statements can be used to manipulate a
  database
• Define a database
• Define tables
• Define columns and their characteristics
• SQL can be used to request rows from a database
• SQL can be used to add, update and delete rows

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Middleware

• A layer of software between your application and
  the database
• Provides a standard interface to any DBMS
• Examples
• ODBC Open Database Connectivity
• Microsoft Products like Visual Basic
• JDBC Java Database Connectivity
• Java

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Benefits of Middleware

• The same object code can be used to access
  different DMBS products
• The application is independent of the data
  communications protocol
• Data can be handled in a format convenient to the
  application

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JDBC

• JDBC provides standard Java interfaces to access
  databases
• It is based on ODBC and supports a subset of what
  ODBC supports
• Database definition and manipulation is done
  using SQL statements
• JDBC is useful because it implements a standard
  interface
• It can theoretically work for accessing any
  database
• A JDBC driver provides a database specific
  connection

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Some JDBC Drivers

• JDBC Driver provides access to a specific
  database
• COM.ibm.db2.jdbc.net.DB2Driver
• Driver from IBM for accessing DB/2 across a
  network
• COM.ibm.db2.jdbc.app.DB2Driver
• Driver from IBM for accessing DB/2 locally
• sun.jdbc.odbc.JdbcOdbcDriver
• Driver from Sun for accessing databases supported
  by ODBC
• ie, MS Access
• oracle.jdbc.driver.OracleDriver
• Driver to access Oracle databases