eaDevil's Blog

ChrisProject

2004-10-12T09:45:00.000-07:00

Introduction,
This document represents the J2EE software architecture of Project X that covers the system.
This document covers:
Internet based presentation tier
Business Logic tier
Middlware, components responsible for communication with the coms/PDA system.
Data Tier

This document does not cover:
The PDA system
The Sensors

Related Documents
Functional Specification
System Architecture
Software Architecture for the PDA systems.
Non functional requirements

Application Structure
The software components shall be separated into tiers. Each tier represents a specific responsibility, and isolates the implementation of that responsibility from the other tiers.

TODO - diagrams p85-p87

The tiers are
Presentation
Business
Data/Comms Tier

To promote re-use, these tiers may share common code components and libraries. Logging code is just one example where tiers may rely on shared software. This sharing shall not couple the layers however, maintianing the desired level of isolation of the components.

The tiers can inter-communicate via specific API's (interfaces) that exist for that purpose. The interfaces to components that are internal to a tier are hidden from components external to the tier. These interfaces are only accessed externally. This is achieved via the facade pattern.

High level components

Presentation Tier components

View
Model
Control

Business Tier components
Business Rules
Security

Data Tier components
Comms Services
Databases

The tiers represent horizontal separations of the responsibilities of the application. Likewise compents shall be segragated vertically, according to the functions they implement within the application.

These separations are taken from the functional specification.
The vertical components are:
Project website
Security
Customer data
Ecommerce
Provision of services

Project website: mainly display of information: content management system.
Security: Authentification/Authorisation/single sign on/session tracking/Security of data and services. [Consider a security consultant here.]
Customer data: capture of customer details, and maintenance of this data by the customer and by administrators. Considerations: web user interface, vallidation, business rules, back up strategies and encryption.
Ecommerce: presenting services to the customer and allowing the customer to purchase subscriptions online.
Provision of services: In the context of the scope of this document, this allows customers online access to the services they have subscribed to, and providing those services.

TODO
Component diagrams

Presentation Tier
The presentation tier shall conform to the model 2 architecture, which uses the Model View Control (MVC) pattern.
Struts Framework. The web pages shall be implemented with Java Server Pages (JSP). JSP's must be view-only, these shall contain HTML and Taglib tags, nothing else. No Java scriptlets or business logic shall appear in the JSP's.
Apache Tiles shall be used to re-use presentation JSP code.
The Struts Validator component shall be used to validate data entered by the user. The Validator places validation specifications into XML configuration files, and removes the need for Form Beans. Only in extreme cases where there is no validator alternative should Java be used for validation.
Client side validation shall be done using javascript that is embedded in XML that is used by the Struts Validator.
All presentation business logic shall be placed inside Struts action classes and associated helper classes.
The control component of the MVC pattern is the Struts action servlet and the associated struts configuration XML file.
The Struts "action" classes shall access data via the Business Delegate pattern. The delegates shall call the appropriate interface of the business layer. This setup comprises the Model component of the MVC pattern.

The business Logic tier
Business logic shall be contained with business objects whose services are exposed by a facade. The facade be implemented by Stateless Session Enterprise Java Beans (EJB's).

TODO
The Data Tier
DAO.
JDBC/Comms.
PostegreSQL

Example activity diagrams, sequence diagrams.

TODO design principles.
Components shall be loosely coupled and have high cohesion.
Adhere to Sun Java coding standards.
Use design patterns appropriately
Use J2EE good practices. Declaritive/XML config file configuration is preferred over hard coding.

PRINCESS: 1,000 PIECE PUZZLE

2004-09-12T15:41:00.000-07:00

PRINCESS: 1,000 PIECE PUZZLE

Where do I fit in??

2004-09-12T15:38:00.000-07:00

You fit in with all those people that do not fit in, to ask where you fit in is one idea and a wonderful query it makes, you may wager to that. Now let me put it to you, and you may go so far as to agree, on a good, day, but allow me to present to you some species of corollary, if that is the word. You see, sometimes, when you ask a question, substitute one word for another!
You see, ask yourself, where do I not fit in? Then you may find that you fit where you think you do not fit in, and you don't fit where you feel you should fit, and only then, will you realise that you are happiest where you do not fit, and are unhappiest where you fit, and then the whole matter as gone to the gods and the devils that you did not expect!

Fiddler On The Roof

2004-09-12T15:04:00.000-07:00

Recently I had the honour of watching the three hour DVD of the classic musical movie, Fiddler On The Roof. The fact that this movie is a musical, and the fact that I have, in my ignorant life, subjected myself to scant musicals (but have perversely enjoyed the musicals I have seen, against all expectations) caused my preconceptions to be inalid. You see, it is simple, I expected a trivial bit of fun. Indeed, this movie goads you into thinking that this is a playful bit of fun... but i am talking too much, and I do not wish to give things away...
So basically know that this is a long movie, there is a kind of interval where the screen goes dark about half way through. When I saw this, after buying the DVD and taking and watching it at Madpole's place, we went for a walk halfway through. We both thought we knew how things would progress.... But I say no more!
Fiddler on the roof has a fanciful title and wonderful music, as you would hope. This is a movie from the days where profits were not the only goal. And it shows. The movie would never be made today. Test screenings would panic Hollywood executives. That is my highest recommendations for this movie.
This movie will piss off juveniles, the only market that Hollywood cares about. So go and see Fiddler On The Roof and you will never look at Jews in the same way. They really do know how to take the mickey out of themselves. In many regards, this movie is Jewish propaganda, but this is the finest kind of propaganda, it is JUSTIFIED propaganda. They say, yes, these are our obsessions, and they are ridiculous. There is so much soul-searching here.
The writing is wonderful. Though the words are fit for simpletons, the language is disappointingly unsofisticated, the ideas, and especially the paradoxes are presented with a most perceptive and pleasing wit.
There are so many incredible exchanges of dialogue to behold here, I learned much about how to handle matters of diplomacy, of duty, of responsibility, of religion. And this depth of ideas is enhanced, not trivialised by the musical inerludes.
This movie is art. love it.

covert people to mozilla and/or firefox!

2004-09-12T14:25:00.000-07:00

The web will not be free until everybody stops using microsoft explorer. I urge everybody to convert people from using Microsoft Explorer to using Mozilla or Firefox browser. Only then will the w3c consortium standards be used and then the whole world will benefit!
By the way, Mozilla and Firefox are so much more wonderful ways of browsing the web!

Zatoichi Movie Review

2004-09-12T11:03:00.000-07:00

Zatoichi Movie Review
Zatoichi is a Japanese Samurai action movie that is easy to watch and yet quite profound at the same time. Read no more, go and see the movie.
This film strikes its pointy weapon right between the deadlights. Whoosh!!!!! [cue suspiciously bounteous sprays of blood]. The magic of Zatoichi is in its invokation of guity desire to see the doddery old man tha tis Zatoichi himself dole out the carvery treatment to swathes of baddie gangsters.
Zatoichi is a symphonist, you see, and his orchestra is a cane, a stick that conceals a cargo of glistening steel. Recent movies parade action heros of the Keanu Reaves/Damon what's his name ilk. Pretty boys; shallow yoofs; catastrophically implausible chicks are the modern action stars that serve to drain one's enjoyment so intensely that one craves to see them die horribly, and begrudges there inevitable victories. Now Zatoichi is a guy that you cheer on with passion. He is, in my opinion, the most watchable action hero since the golden days of Schwartzenegger and Sean Connery Bond. It's curious how different from one another these guys are, it goes to show that Hollywood's attempts to assuage risk by blindly following cliche are gravely counter productive.
Zatoichi, in his blindness provides philosphy, it questions the value of our senses. This may seem unorigional, but the original Zatoichi movies stretch back a long way, so the heritage at least is innovative. Here we have a playful representation of intriguing concepts, sensory information can hinder or help, depending upon factors that are generally outside of our experience. The greatest mathematical genius of them all, Leonard Euler, upon losing the sight in an eye, declared his good fortune as "one less distraction".
(I read an interesting mathematical fact recently, that mathematicians like to name mathematical things after the first mathematician to discover them *after* Euler!)
Admittedly Zatoichi would kill rather than prove things, as was Euler's wont, such as "e" is an irrational number, but the former, though vulgar, works better on film. Arguably.
There is something deeply beguiling about Zatoichi's handicap being the source of his strength. One inferior Hollywood take on this idea was in "The Phantom", a movie that can't hold a candle to Zatoichi's searing neutron star. The Phantom has a dull pretty boy hero to enhance the audience's abject misery.
In contrast Zatoichi inspires me to question life a little, and take up the subject with people that are curious about the perplexing nature of perception and identity. Sight is too precious to give up lightly. Pun unintended. (My subconscious is to blame for that!). But Zatoichi can tell us something about how to deal with loss in general. Have you been deprived of a possession or bereaved in some way? Zatoichi infuses us with the idea that from deprivation can come enlightenment. Not all bad news can be compensated for perhaps, but in my life, it is amazing how often I have cursed events with unrepeatable language, only to look back and realise that I benefitted in some unlooked for fashion.
When I recall the Kill Bill movies I don't remember having any thoughts other than how much they sucked. They were quite simply empty, mildly entertaining, but as far as inspiring any kind of life enhancement is concerned, they fail. Great movies affect your opinions and though Zatoichi is a relatively low brow movie, it still causes the mind to slash at the criminal preconception within.

Spoilers
There was something spell binding about watching Zatoichi hobbling towards his foes with the tardy inevitability of the Reaper himself.
The musical dance routine at the end was inspired.

Note,
This is a draft review for my eadon site eadon.com if this review hasn't appeared there yet, then it shall soon!

Links To Do

2004-09-12T02:20:00.000-07:00

Links:
Gnomoradio
3rd manifesto database
xerces.org
http://www.pubpat.org