??????? J2EE ??????????? Oracle

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??????? J2EE ??????????? Oracle
Mr. Liran Zelkha, Chief Architect Liran.zelkha_at_alu
nasoft.com
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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

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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

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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?

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Middletier Application Needs

• All we were used to
• Functionality
• User interface
• RAD
• And some more
• Security
• Performance
• Management
• Upgrade-ability
• Integration

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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.

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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.

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J2EE Tiers
Client machine
Firewall / Load Balancer
Web Server
EJB Container
Web Container
EJB JDBC JCA JMS
Database
HTML GIF JPEG
Browser
Servlet JSP
Web Server
EJB Container
Web Container
EJB JDBC JCA JMS
HTML GIF JPEG
Servlet JSP
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J2EE Scenario
Client machine
Web Server
EJB Container
Web Container
Connection
Connection
Connection
Database
1
3
Datasource
4
7
6
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Catalog.jsp
BookEJB
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5
HTTPSession
Logo.gif
http//www.j2eedemo.com/catalog.jsp
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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.

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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.

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Demo Web Tier Ease Of Use
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The Business Tier

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

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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.

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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.

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Demo Business Tier
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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.

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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.

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J2EE Benefits - Experience

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

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The Middle Tier future

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

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Web Services

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

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SOA

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

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Development Aids

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

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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

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XP eXtreme Programming

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

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AOP - Aspect Oriented Programming

• Many view J2EE containers as AOP containers
• Write business logic
• Server provides aspects of transactions,security,
  performance, etc.

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Web Services Meet Business Processes
Web Service 1
Web Service 4
Web Service 2
Web Service 5
Web Service 3
Web Service n
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Example Problem Space
Credit Service
Consolidate Results
PO Service
Client
Inventory Service
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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

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Q

Q U E S T I O N S A N S W E R S
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