JHeadstart The Next Generation Lucas Jellema, AMIS Services OTDUG 2004

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JHeadstart The Next Generation Lucas Jellema,
AMIS Services OTDUG 2004
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Agenda

• How to approach Java/J2EE Web Development
• Early and Major Decisions
• Analysis
• Development Environment setup
• Application Configuration
• Overview JHeadstart 10g
• Supported Frameworks
• Main functionality and benefits
• Real life project experiences
• Extending JHeadstart applications with
• PDF report generation
• SVG based graphics

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Early and Major decisions

• Tools and Technology
• First round
• Persistent Data storage RDBMS
• Application middle tier Java
• Client HTML (and PDF, Email, XML)
• Choose the Database, Java IDE and J2EE
  Application Server
• For example Oracle RDBMS, JDeveloper, OC4J
• MVC Architecture
• Second Round
• Model implementation (OO/R mapping framework)
• View implementation (HTML render engine)
• Controller implementation
• Reusable libraries, code generators, supporting
  tools

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The RDBMS

• Role of Database what is your primary concern?
• Be truly J2EE theory compliant
• Prevent vendor lock-in at all costs
• Use the RDBMS as simply as you can
• Bring data processing to the Java middle tier
• vs.
• Benefit from RDBMS functionality as much as you
  can
• Use your organizations skills to the fullest
• Cater for different applications and/or
  technologies accessing the database

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Model implementation OO/R Mapping Framework

• Model implementation
• Turns Objects into persistent Database Records
• Retrieves data from the RDBMS and instantiates it
  into Object
• Provides services for querying, inserting,
  updating and deleting, locking, caching data
• based on JDBC
• All based on a mapping description between
  Objects and Tables/Views, Properties and Columns
• Most prominent OO/R Mapping Frameworks
• Toplink, Hibernate, JDO, Castor, ORJ, BC4J/ADF
  Business Components, DIY

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JHeadstart supports Toplink and ADF Business
Components

• Official support for Toplink recently added
• As of JHeadstart 10g (9.0.5.1) (June 2004)
• Inofficially available since September 2003
• As far as JHeadstart is concerned, it is
  transparent whether you use Toplink or ADF BC
• JHeadstart uses ADF BC for its Meta Data
• Generally speaking
• ADF BC is much more Database aware
• More productive for SQL skilled developers
• Toplink is much more OO
• Will be acceptable to J2EE people
• JHeadstart can best be used with ADF BC
• However a mix of the two is also an option

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View implementation Render Engine

• HTML
• Java Server Pages (JSP)
• Including JSTL (JSP Standard Tag Library)
• Oracle UIX (User Interface XML)
• Implements Oracle Browser Look Feel guidelines
• Soon to be an Java Server Faces (JSF)
  implementation
• Other output formats rendered to client
• Email using utl_mail or JavaMail
• XML using Oracle XDK, XSLT transformation
• PDF using XML, XSL-FO and Apache FOP

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Controller Implementation

• Struts
• Apache Jakarta

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JHeadstart supported frameworks and technologies
Browser
View (UIX and/or JSP)
Controller (Struts)
JHeadstart Runtime Framework
Model (ADF Business Components and/or Toplink)
(Oracle) RDBMS
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Other decisions

• Analysis and Design
• UML
• ERD
• Screen Design and Prototyping/Mockup
• Database Design and Development
• Oracle Designer
• JDeveloper
• Generation vs. Coding
• Tasks and Roles in the project team
• required skills
• Business Logic implementation
• Where (and how) do you implement business rules

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Consolidate Business Rules in Database
Browser
Client
Application server
Server Side (Data Oriented) Business Logic
Database
Data
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Beware.

• Try to only build application logic that is
  specific to your business
• Do not spend
• large portion of the budget
• substantial period of time
• your best resources
• on building generic infrastructure
• Reuse infrastructure!!!
• Compare Oracle Forms and what the Forms Runtime
  engine does for your application
• You run the risk of building your own Java/J2EE
  Forms Runtime engine!!!

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Analysis

• Interfaces
• Incoming and Outgoing
• Client tier, Middle tier, Database
• Synchronous and Asynchronous
• Performance, Security, Responsibility
• Complex, Non generatable UI constructs
• Reporting
• Metrics
• Average and Peak numbers of (concurrent, active
  users) and what does an active user do?
• Required response times
• Security

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Environment Setup

• File based vs. Repository Based
• Implement a system for Version Control
• Look out for bottle-neck files
  struts-config.xml, application structure.xml, ADF
  BC
• Set up incident management system
• Bugzilla
• Implement automated unit testing
• JUnit and HttpUnit
• Learn how to remote debug the web application
• Define, publish and enforce Coding Standards

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Example Coding Standards

• No Java Code in JSPs (use Custom Tags)
• No hard-coded values in Java code (or
  JavaScript) use a Constants class or (for
  strictly private values) use private final
  members at the beginning of a class.
• Text that is presented to the user must be
  included in ResourceBundles, either Struts-style
  server-side or in a JavaScript library. No
  boilerplate may directly be included in a JSP or
  Java Class only keys to entries in
  ResourceBundles are allowed
• Every public and protected method must have
  JavaDoc style comments
• Every public and protected method must have an
  automated (J)Unit-test
• No style definitions in a JSP that also applies
  to the style attribute in HTML elements all
  styles must be defined in external CSS-files
• No JavaScript (except for event-handlers) in a
  JSP all JavaScript code must be defined in
  external JavaScript libraries

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Environment Setup (2)

• Make use of automated build and task execution
• Ant
• Synchronize all filesystems with SCM, Nightly
  build, JavaDoc generation, regression testing
• Set up Performance Testing tools
• Microsoft Web Application Stress (WAS) tool
• Apache JMeter
• Ensure internet access for all developers
• Google is your best friend
• Assemble knowledge, expertise and experience
• Early on! You make or break the project with the
  earliest decisions

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Application Configuration

• Which versions and edition of the technologies
• For example JSP with JSTL? Oracle 10g EE
  database features?
• Extend framework classes
• To provide hooks you may later need
• Stylesheets and templates
• Consider Struts Tiles for highly customizable
  look feel
• Text presented to the end user
• Language, Type of User, Role
• boilerplate, data, messages, on line help
• Logging
• Authorization and Security

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JHeadstart 10g Overview

• JHeadstart provides
• An easy entrance into Java/J2EE development of
  OLTP-like (data intensive) applications
• High productivity for development of common and
  complex constructs
• Through generation and reusable components
• Infrastructure around standard technologies
• Glue between Controller/View and Model
• JHeadstart supports key technologies
• BC4J/ADF Business Components and Toplink
• JSP and Oracle UIX
• Struts (and the Oracle MVC Framework/Cleveland)
• JHeadstart comes with source code
• and can be extended

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De Europeesche Travel Insurance for Consumers
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Joint Aviation AuthoritiesAirplane Audits
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University of AmsterdamCourse Management and
Publication
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TMITracking and Tracing
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AMIS Library System
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Adding PDF report and SVG Graphicsgeneration to
JHeadstart applications

• Many web-applications require some form of
  reporting, either through Excel or PDF
• The foundation for both is XML
• Using Apache POI you can generate Excel from XML
• Using Apache FOP you can generate PDF from XML
• You can produce Scalable Vector Graphics from XML
• JHeadstart can easily be extended to cater for
  these types of output
• These are alternative View implementations
• Driven from the same Model implementation the
  JSPs work from

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How to produce PDF output?
OutputDocument
PDF, PS, SVG RTF, XML, (XHTML)
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Extending JHeadstart with PDF and SVG generation
Browser
html, PDF, SVG
View
Controller (Struts)
JSP
FOP
JHeadstart Runtime Framework
XDK
2XML
Model (ADF Business Components and/or Toplink)
(Oracle) RDBMS
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Oracle 10g JDeveloper ADF Application
Development Framework

• ADF promises Productivity with Choice
• Choice several different technologies for M, V
  and C
• Productivity visual editors, wizards, click
  drag drop, generate
• Oracle has proposed a JSR to standardize the
  concept of ADFs Data Binding
• 1.0 Release of ADF April 2004
• JHeadstart ADF release end of Summer 2004
• Considerations surrounding ADF
• How stable/mature/complete?
• What happens when click drag drop are not
  enough?
• Is ADF an Oracle specific venture apart from the
  main stream of Java/J2EE offerings?

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Discussion and Conclusions

• J2EE Development
• Major Decisions
• Analysis
• Environment
• Application Configuration
• JHeadstart
• Easy entrance, productivity, infrastructure
• Source code is provided
• JHeadstart is very extendible, e.g. PDF SVG
• Future
• ADF? JSF? Struts 2.0? JDO?

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The End

• For questions send an email to jellema_at_amis.nl
• For more information, scripts and examples go to
  www.amis.nl/technology