This week's giveaway is in the Programmer Certification (OCPJP) forum.
We're giving away four copies of Java Mock Exams (software) and have David Mayer on-line!
See this thread for details.
Win a copy of Java Mock Exams (software) this week in the Programmer Certification (OCPJP) forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic

AJUG: Layers in SUN World

 
Oghie Ojior
Greenhorn
Posts: 15
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Layers are logical units in software. Each layer in the software is responsible for a specific task in an application.
In theory there are 6 layers in software:
Presentation manager
Presentation logic
Application logic
Business logic
Database logic
Database manager
Are these the same layers SUN is referring to?
 
Ajith Kallambella
Sheriff
Posts: 5782
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
"Tier" is perhaps a better parlance than "layer". In the J2EE world, we always speak of three prominent tiers viz., Client Tier(aka Presentation tier), Application Tier( aka Middle Tier) and the Database Tier(aka Persistence tier ). Some architectures include an Enterprise Information Systems(EIS) tier in addition to/instead of Database Tier. The entire set of component technologies offered by the J2EE platform can be divided into these four tiers.
The term layer is often used in the context of design patterns, to distinguish the boundaries between collaborating components. Pesonally I prefer using the term "tier".
Cheers,
 
Jack Zhou
Ranch Hand
Posts: 94
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I think, term tier focus on the physical distribution for your application components. Layers are a way to organize the softeware pieces according to their functionality. So I understand in a 2-tier app with a fat client. The client tier could contain both the persentation layer and business logic layer. a 2-tier app with a thin client, the business logic layer is on the server tier. May be most of time, tier and layer align with each other. I would think more layrs increases maintanablity and flexbility while more tiers decrease the managebility. Just my opinon
 
Joseph Zhou
Ranch Hand
Posts: 129
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
There is SunTone methodology describes 3 aspects of an architectural framework
1.tiers - application partitioning
client
presentation
business
integration
resources
2.layers - hardware/software stack
application
virtural platform - API or spec.
upper platform - middleware
lower platform - OS
hardware
3.Systemic qualities
the 8 characteristics: performance...
 
Happiness is not a goal ... it's a by-product of a life well lived - Eleanor Roosevelt. Tiny ad:
the new thread boost feature: great for the advertiser and smooth for the coderanch user
https://coderanch.com/t/674455/Thread-Boost-feature
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!