A presentation of J2EE

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A presentation of J2EE Powered By Docstoc
					      ‫ וטכנולוגיות‬J2EE ‫פתרונות‬
                      Oracle



Mr. Liran Zelkha, Chief Architect
Liran.zelkha@alunasoft.com
Agenda
• From client-server to N-tier
  – Middltier application needs
• J2EE application architecture
  –   The Web user interface
  –   The Business tier
  –   Other services
  –   Where to put the business logic
      (Database/Application)
• J2EE benefits
  – Cross platform
  – RAD development
• The Way ahead: Services & SOA         2
Client/Server Applications
• Around since the mid-80s.
• Client power.
• RAD development (VB,
  Developer/2000,
  PowerBuilder).
• But:
  – Installations and maintenance
    (TCO)
  – Do not fit the “web paradigm”

                                    3
N-Tier
• More server oriented.
• Application can be divided to tiers,
  each responsible for different
  aspect of the application:
  – Easier upgrading
  – Easier support
• But:
  – Our requirements have increased
  – Where is our RAD?


                                         4
Middletier Application Needs
• All we were used to:
  – Functionality
  – User interface
  – RAD
• And some more:
  –   Security
  –   Performance
  –   Management
  –   Upgrade-ability
  –   Integration
                               5
J2EE Introduction

• Built on top of Java.
  – Cross platform.
  – Industry support.
  – Large developers base.
• Specification developed and
  maintained by JCP.
  – Check www.jcp.org for list of
    participants.

                                    6
J2EE Current Status

• Oracle, IBM, BEA and Jboss
  largest players.
• Many enterprise software
  vendors use J2EE – SAP,
  Oracle, IBM, PeopleSoft.
• Large number of customers.
• Wide experience and
  acceptance.

                               7
           J2EE Tiers
                                                       Web       Web         EJB
                                                      Server   Container   Container



                                                                              EJB
                           Firewall / Load Balancer




                                                      HTML                   JDBC
                                                       GIF      Servlet       JCA
Client machine




                                                      JPEG       JSP          JMS      Database
                 Browser




                                                       Web       Web         EJB
                                                      Server   Container   Container



                                                                              EJB
                                                      HTML                   JDBC
                                                       GIF      Servlet       JCA
                                                      JPEG       JSP          JMS           8
           J2EE Scenario
                      Web       Web Container       EJB Container
                     Server




                                                    Connection

                                                                  Connection

                                                                               Connection
Client machine




                 1         3                           Datasource                               Database
                                   4
                                                                               7
                       2                        6
                                  Catalog                        BookEJB
                                    .jsp
                                                                                            8
                                        5

                     Logo.gif    HTTPSession


                                                                                                     9
                       http://www.j2eedemo.com/catalog.jsp
The Web Tier
• Use JSP for web development.
• HTML pages with Java code
  embedded inside (much like
  ASP).
• Many supporting technologies:
  –   Session management,
  –   I18N,
  –   Security,
  –   Much more.

                                  10
Web Tier Ease Of Use
• Frameworks for web development
  consolidated into JSF.
• Pre defined components (trees,
  lists, templates) that can be
  purchased or downloaded for free.
• Standard supported by all J2EE
  vendors.
• Tools offer WYSIWYG and RAD.


                                      11
Demo:
Web Tier Ease Of Use
The Business Tier

• Component based
  development.
• Services provided by
  application server:
  –   High availability,
  –   Security,
  –   Management,
  –   More.

                           13
EJBs

• Components for business logic
  (session EJBs), database
  access (entity EJBs)
• Support for remote calls and
  web services
• Application server provides run
  time services – transactions,
  security, more.

                                    14
Other services

• Messaging
  – JMS – standard API for all
    messaging platforms.
• Integration
  – JCA – buy or develop
    connectors for legacy systems.
• Management
  – JMX – easy to develop
    management components.
                                     15
Demo:
Business Tier
J2EE Benefits – Cross platform

• Can work on any
  hardware/OS – Linux,
  Windows, UNIX and
  Mainframe.
• Can work with any vendor –
  commercial (Oracle, IBM) or
  open source (Jboss, Apache)
• Porting is easy.

                                17
J2EE Benefits – RAD

• Setting up server is as easy as
  opening a ZIP file (Oracle,
  Jboss).
• Development can be done
  using RAD tools (Jdeveloper,
  Eclipse).
• Deployment is a mouse click
  away.

                                    18
J2EE Benefits - Experience

• Tons of books, articles, forums.
• Design patterns and blue prints
  for easy development.
• Many online and classic
  courses.




                                     19
The Middle Tier future

• Welcome to the world of:
  – Web services,
  – SOA,
  – Aspect Oriented Programming




                                  20
Web Services

• Components with HTTP access.
• Can be used from any
  language.
• Thoroughly supported in J2EE.
• Can pass through firewalls.




                                  21
SOA

• Service Oriented Architecture.
• Software architecture
  composed of standalone
  components.




                                   22
Development Aids

• AOP - Attribute Oriented
  Programming
• XP
• AOP – Aspect Oriented
  Programming
• BPEL – Business Process
  Execution Language


                             23
AOP - Attribute Oriented
Programming
• J2EE components require
  meta-data:
  – Web.xml, ejb-jar.xml,
    application.xml
  – Proprietary files
• External is an advantage?!?
• Xdoclet can auto-create
  meta-data files

                                24
XP – eXtreme Programming

• Automated testing:
  –   Junit
  –   JUnitPerf
  –   HTTPUnit
  –   Cactus
• Rapid build:
  – ANT


                           25
AOP - Aspect Oriented
Programming
• Many view J2EE containers as
  AOP containers
  – Write business logic
  – Server provides aspects of
    transactions,security,
    performance, etc.




                                 26
Web Services Meet Business
Processes


  Web                  Web
Service 1            Service 4


  Web                  Web
Service 2            Service 5


  Web                  Web
Service 3            Service n

                                 27
Example Problem Space



                                     Credit
                                    Service
          Purchase    Consolidate
           Invoice
            Order       Results

                     PO Service
 Client


                                    Inventory
                                     Service
                                                28
Summary
• J2EE has been here a while and it is
  here to stay.
• Easy to use – unlike a couple of
  years ago.
• Easy to teach – allot of experience
  going around.
• Stable and inexpensive –
  competition brings the best in
  vendors.

• Good luck…
                                         29
QUESTIONS
ANSWERS



            30

				
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posted:3/18/2013
language:English
pages:30