3. Portlet Framework
GenericPortlet class is not the only way of developing
portlet.
Several framework are nowadays available to develop
portlet:
Struts
JavaServer Faces
Spring
3
4. Liferay MVCPortlet
Make use of a subset of the classical MVC Framework
Easier to use
Faster learning curve
Less configuration files to deal with and to synchronize
with java sources
MVC: ModelView Controller paradigm helps keeping the
code tidy
4
5. Model View Controller
Controller
View Model
5
Model: layer responsible to hold the data and the
business logic to manipulate them. In case you use
Liferay Service Builder to manage your data, it
works at the model layer level.
View: layer containing the rules to display data to
the users (typically the JSP pages)
Controller: layer behaving as traffic director.
Determine which action will be executed according
users input. Model andView layer shouldn’t
communicate each other but interact with the
controller
6. Difference from the GenericPortlet
Unnecessary implementation of doView() and doEdit()
and any others porlet API
Class is simpler, it contains just the action methods
In case you really want to use any portlet API they are
available, MVCPorlet is a subclass of the GenericPortlet
class
6
7. Portlet accessing data
Several reasons to use a database behind a portlet
Java Programming offers different approach to deal with
data
Object-relation mapping framework allow database
access in a robust way. Java offers Persistence API (JPA)
for database access
Liferay uses Hibernate to manage all its data
7
8. Drawback in Hibernate direct usage
Development of independent
portlets using Hibernate/JPA
appears to work, but the
runtime implications are not
immediately recognizable:
• Stale caches because of multiple
writers.
• Server resource consumption
for multiple DB connections,
memory usage for runtime
copies of Hib/JPA objects.
• Synchronization issues (two
portlets given new Hib/JPA
config but one forgotten).
Source:8
9. The Service Builder Solution
Service Builder
provides a single point
to share code (DB
access and business
logic) to independent
portlets, resolving the
caching, resource, and
synchronization issues.
Source:9
