Web Application Development
Introduction to application servers, web applications
and portlets
Riccardo Rotondo
riccardo.rotondo@ct.infn.it
Catania, 10/03/2014
Outline
}  Scenario
}  Application
Server
}  Web Application
}  Portlet
2
Scenario
JSR 168/268
JSR 168/268
JSR 168/268
JSR 168/268
Catania Science Gateway Framework
GRID
CLOUD
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Local Cluster
Web enviroment
}
}
}
Application Server (Glassfish)
Web application working as Portlet Container (Liferay)
Portlet (a custom application designed under users needs)
JSR 168/268
JSR 168/268
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JSR 168/268
JSR 168/268
What is an application server?
A software framework designed to host applications
running in a web environment
}  Most of them contains a service layer model
}  A set of API is available for the developers to access the
application server’s functionalities
}  As long as the management of the environment is
demanded to the application server, developers can focus
on the business logic.
}
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Most popular application servers
http://plumbr.eu/blog/most-popular-application-servers
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What is a web application?
An application accessed over a network
}  Analogy with “common” applications
}  User interact with them through a web-browser
}  A web applications can offer thousands of services: Liferay
is a web-application
}
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Liferay (www.liferay.com)
Highly-configurable, scalable, open source
portal framework;
}  Compatible with JSR 168/286 standards
and based on modern web 2.0
technologies;
}  Liferay services currently used:
}
}
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Portal;
CMS & WCM;
Collaboration and “social” software
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Liferay Plugins
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Portlets
Themes
Layouts
Hooks
Exts
What is Porltet ?
Defined in the Java Specification Request (JSR
168/286)
}  A porlet is a web component able to set a frame
portion of a web page.
}  Differently from Servlet it needs a Porltlet
Container to allow the user to interact with it.
}  Standard Portlet can be deployed in any Porlet
Container in case they will use standard libray.
}
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Generic Porlets Life Cycle
YES
NO
End of
Services?
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Generic Porltlets Interface Method
Class GenericPortlets {!
init (PortletConfig);!
processAction (ActionRequest,
ActionResponse);!
render (RenderRequest, RenderResponse);!
destroy();!
doView (Request, Response);!
doEdit (Reuqest, Response);!
doHelp (Request, Response);!
}!
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Portlet Mode
}  A porltet
works in three
different states.
}  View Mode: generate a
markup ( a portion of a
web page);
}  Edit Mode: allow portlet
customisation and
setting preferences.
}  Help Mode: explains
portlet functionalities.
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Action Request
Action
Request
view.jsp
processAction()
Action
Request
edit.jsp
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Render
Request
doView()
edit.jsp
doEdit()
view.jsp
Render
Request
processAction()
Render Request
Render
Request
view.jsp
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doView()
view2.jsp
Portlets
}
}
Standard JSR168/286
Interaction between jsp pages and java code
Application Server (Glassfish)
JSP page
<jsp:useBean!
<form … >!
!
<input … />!
</form>!
}
}
Java code
Class <you portlet>!
Extends
GenericPortlet …!
!
JSP uses <form… statements to send parameters to Java code
Java code extends class GenericPortlet overriding methods:
}
Init, doView, doHelp, doEdit, processAction!
Java code uses 2 Classes to exchange data from/to JSPs!
}
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Portlet
files (root)
!
build.xml!
!
docroot/!
WEB_INF/!
css/!
images/!
js/!
!
jsp_page_1.jsp!
…!
jsp_page_n.jsp!
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Used by ‘ant’ to compile and
deploy the portlet
Define here JSP’s styles
JSP image files
JavaScript files
Portlet JSP pages
Portlet files (docroot)
WEB_INF/
glassfish-web.xml
web.xml
lib/
Job/
liferay-display.xml
liferay-plugin-package.properties
liferay-portlet.xml
portlet.xml
src/
<package_name>/code.java
tld/
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Used to define database and other
resources settings
Jar Library directory (local scope)
Job files (Custom dir)
Portlet
configuration files
Java source files
XML structure file
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Building environment
Get Liferay with Glassfish
}  Customising Liferay installation (database
connection)
}  Get Liferay plug-in SDK
}  Configuring Netbeans (optional)
}
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Deploying first portlet
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Understanding ant scripts
Creating “hello world” portlet
Understanding portlet files
Compiling porltet
Deploying porlet
Understading portlet management on the server
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References
Liferay: https://www.liferay.com
}  Liferay Bundles:
https://www.liferay.com/downloads/liferay-portal/availablereleases
}  Liferay Plugin SDK:
https://www.liferay.com/downloads/liferay-portal/
additional-files
}  Netbeans: https://netbeans.org
}  Netbeans liferay plugin:
https://contrib.netbeans.org/portalpack/
}
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Questions ?
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