git + gitolite + git-daemon + gitweb setup on Ubuntu 10.10 server

Reference:

http://computercamp.cdwilson.us/git-gitolite-git-daemon-gitweb-setup-on-ubunt

Installing Maven Plugin (M2Eclipse) in Eclipse

1. Download eclipse-jee-galileo-SR1-win32.zip
2. Extract this file, and rename eclipse folder to eclipse-jee-galileo-SR1
3. Go to eclipse-jee-galileo-SR1-win32 folder and open eclipse.ini file
4. Add -vm argument to it, like...

-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
-vm
C:\SUN\Java\jdk1.6.0_17\bin\javaw.exe
-vmargs
-Xms40m
-Xmx256m




5. Install Subclipse 1.6.5 from http://subclipse.tigris.org/update_1.6.x



6. Install AJDT 2.0.1 from http://download.eclipse.org/tools/ajdt/35/update



7. Install M2Eclipse from http://m2eclipse.sonatype.org/update

Aggregation Vs Composition

Aggregation:

• Weak “has-a” relationship between aggregate (whole) and component (part), as component object may survive without aggregate object.

• Component object may be accessed through other objects without going through the aggregate object.

• Aggregate object does not participate in the life cycle of component object, meaning the component object may outlive the aggregate object.

• State of component object still forms part of the aggregate object.

Example: History-Class object contains zero or more of Student objects. The state of each Student object has an influence on the state of the History-Class object. If the History-Class object is destroyed, the Student objects may continue to exist.

The UML diagram above illustrates the aggregation association line with an open diamond on the aggregate side.

Composition:

• Strong “has-a” relationship between the composite (whole) and component (part), as the composite object takes ownership of the component, meaning composite is responsible for creation and destruction of the component parts.

• Component may only be part of one composite.

• If the composite object is destroyed, all the component parts must be destroyed, or the reference and responsibility of the component part must be handed over to another object.

• Composite enforces encapsulation as the component parts usually are members of the composite objects.

Example: House object contains zero or more Room objects. The state of each Room object has an influence on the House object. If the House object is destroyed, the Room objects will also be destroyed.

The UML diagram above illustrates the composition association line with a solid diamond on the composite side.

Ruby on Rails on Red Hat

http://www.redhat.com/magazine/025nov06/features/ruby/

Nice article about Wicket

I am working on a project, where we are using Light Portal. But, for some of my requirement I need custom UI based on binding methods like in JSF. So I was thinking if Struts or JSF or Spring WebFlow fit into my requirement. Browsing internet I found this nice tutorial about Wicket web framework, and found very interesting. Just want to share the link...
Wicket Impressions, moving from Spring MVC / WebFlow

Hibernate Caching: Simplest approach to understand

Today, I read this article about Hibernate Caching and found it very simple to understand. This describe everything related to caching in few words, starting from... what is cache, how many type of caching is there in hibernate, how many caching implementation hibernate support, and how to implement them. Meaning everything is just few word. This made this article as a study notes for beginners. Just want to share this link... Introduction to Hibernate Caching.