Session # 2645 Reusable Development Components from the Java(TM) 2 Platform, Enterprise Edition (J2EE(TM)) and Open Source Projects Rob Weaver Architect Quovera

Session # Overall Presentation Goal or Primary Purpose Building reusable development components helps us decrease time to market and increase software quality.

Session # Learning Objectives As a result of this presentation, you will be able to: –Understand “real world” reusable component development –Know about some of the strengths and weaknesses of reusable code –Learn some best practices.

Session # Qualifications Quovera (formerly Millennia Vision Corporation) Founded in 1995 as “Millennia Vision Corporation (MVC)” Strong High-Tech Industry Background Profitable 5 Years Without Outside Funding Experience Consultants with 10+ years experience Over 200 clients for whom we have completed over 300 projects Differentiators Architecture Technology Office (ATO) Program Management Office (PMO)

Session # Qualifications Rob Weaver is a Web Architect for Quovera –Member of Quovera’s Architecture and Technology Office. –Proponent of the web since 1995 when he joined Excite to become a webmaster.

Session # Qualifications Will Andrews –Technical Director for Quovera –Member of Quovera’s Architecture and Technology Office. –Has been web enabling applications since 1997 at PricewaterhouseCoopers.

Session # Reuse: the Holy Grail of software development We can be freed from making the same mistakes over and over again, and happily pursue finding entirely new ones. Reuse is one of the benefits of an object oriented language because OO is built around it.

Session # Agenda Introduction Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # Reusable code – more design, less development Architecture and Technology Office Modeled Systems (ATOM) Reference Framework Architecture –Technologies –Reusable Components –Additional Services –Layers –Design Pattern Information Flow

Session # Reusable code – more design, less development Open Source projects –Open source components need to be well understood Design considerations –Keep framework lightweight –Components need to be flexible

Session # Open Source projects Apache ( Tomcat ( Struts ( JDOM ( Netbeans (

Session # Design considerations Keep framework lightweight Components need to be flexible Open source components need to be well understood

Session # Agenda Introduction Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # Eating our own dog food Quovera Time and Accounting Secure web-deployed time and expense (TimeX) reporting module –Mission-critical for a consulting company –Replace Excel solution Easy to use Leverages reusable components –Database design –Back-end PL/SQL utilities ( , user security, etc.) –Java classes Fast –Light-weight client –High availability

Session # Design Decisions JSP solution –Fulfills high-availability, fast, web-enabled requirements Base the system on Quovera ATOMS and Reference Framework –Architecture and Technology Office Modeled Systems Uses Model-View-Controller architecture

Session # Model-View-Controller (MVC) SmallTalk strategy recently promoted by Sun Model = data and values, validation, ranges View = display Controller = what happens when user interacts with the component M CV

Session # More on MVC The MVC separation allows you to plug in different front-end clients Provides a separation in development, too –Model is driven by data design –Controller is driven by process design –View is driven by screen design Different development skills for different styles of presentation (application vs JSP) Swing attempted this but ended up with a separable model architecture –View and Controller layer are merged M CV

Session # Agenda Introduction Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # Reference Framework Architecture Design Pattern Information Flow

Session # Reference Framework Architecture Technologies

Session # Reference Framework Architecture Reusable Components

Session # Reference Framework Architecture Additional Services

Session # Reference Framework Architecture Layers

Session # TimeX MVC Usage Single servlet for Controller function –Business logic is provided by support classes (Handlers) Handlers use data objects (classes) to interact with the database (Model) –Usually static methods to call a SQL statement or database procedure One handler per JSP –This supplies the View

Session # Process Summary

Session # Process Summary 1.Call servlet 2.Gather request parameters, store session info 3.Check privileges 4.Get the proper handler 5.Initialize the handler, validate if necessary 6.Check the request action sent ( LOAD, FORWARD,SAVE_FORWARD, SAVE_LOOP 7.Get next handler if action is FORWARD or SAVE_FORWARD 8.Dispatch request to the proper JSP

Session # Struts Components and Request Lifecycle

Session # TimeX User Interface Login Select a time period

Session # Enter Time One day at a time

Session # Submit Time Report Employee is done with report Status changes to submitted Approver must review and approve

Session # Expense Report Follows similar flow up to the entry form

Session # Quovera Time and Expense Reporting Requirements Secure web-deployed time and expense (TimeX) reporting module –Mission-critical for a consulting company –Replace Excel solution –Easy to use

Session # Quovera Time and Expense Reporting Requirements Leverages reusable components –Database design –Back-end PL/SQL utilities ( , user security, etc.) –Java classes Fast –Light-weight client –High availability

Session # Design Decisions JSP solution –Fulfills high-availability, fast, web-enabled requirements –Base the system on Quovera ATOMS and Reference Framework

Session # Design Decisions Utilize Open source components Uses Model-View-Controller architecture –Model-View-Controller (MVC) Model = data and values, validation, ranges View = display Controller = what happens when user interacts with the component

Session # TimeX MVC Usage Single servlet for Controller function –Business logic is provided by support classes (Handlers) Handlers use data objects (classes) to interact with the database (Model) –Usually static methods to call a SQL statement or database procedure One handler per JSP (View)

Session # Agenda Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # Challenges in utilizing the framework Client dictates technologies Components often have dependencies Some risk when compared to commercial products

Session # Agenda Introduction Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # Summary You are already using reusable development components when you code in Java ! Design patterns are more reusable than components Open source is useful and fun Blah, blah, blah … End

Session # Agenda Introduction Example of using reusable components Design decisions and patterns Reference Framework Challenges Summary Q & A

Session # 2645

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Session # 2645