eXo platform

Benjamin MestralletSoftware ArchitecteXo platform SARL

Portlet API in Action

BeJug Workshop 2004

Overall Presentation Goal

Let's implement and deploy your first HelloWorld portlet in a JSR 168 certified portlet container

Speaker’s Qualifications

● Benjamin Mestrallet is a software architect● He co-leads the eXo platform project● He created the eXo platform SARL which is a

service company that focuses on training and support for the eXo platform

● We published two articles about the eXo platform on TheServerSide.com

Ease of use

• We make your life easier• Code faster• Deploy faster• Go home earlier

Presentation Agenda

● Part I : the Hello World portlet• The code• The eclipse plugin

● Part II : a portlet framework?

● Part III : Architecture of the eXo platform• Integrated application suite• IoC / dependancy injection• The services stack• The standards

MVC design

● Controller : Portlet● Model : JavaBeans● View JSP

Redirection

● Redirection to the JSP : PortletRequestDispatcher

private static final String HELLO_TEMPLATE = "/WEB-INF/templates/html/HelloWorld.jsp"; public void doView(RenderRequest pRequest, RenderResponse pResponse) throws PortletException, IOException { pResponse.setContentType("text/html"); PortletContext context = getPortletContext(); PortletRequestDispatcher rd = context. getRequestDispatcher(HELLO_TEMPLATE); rd.include(pRequest, pResponse); }

The JSP

<%@ taglib uri="http://java.sun.com/portlet" prefix="portlet" %><portlet:defineObjects/><center> <img src='/HelloWorld/images/hello-world.png'/></center><center>HelloWorld Portlet in <b><%= renderRequest.getPortletMode().toString()%></b> Mode</center><center>The current window state is <b><%= renderRequest.getWindowState().toString()%> </b></center>

The portlet.xml <portlet> [...] <portlet-name> HelloWorld </portlet-name> [...] <portlet-class> HelloWorldPortlet </portlet-class> [...] <supports> <mime-type>text/html</mime-type> <portlet-mode> edit </portlet-mode> <portlet-mode> help </portlet-mode> </supports> [...] </portlet>

2 phase requests

Specs 1.0

PortletURL

● 2 types : ActionURL and RenderURL

PortletURL actionURL = pResponse.createActionURL(); actionURL.setWindowState(WindowState.MAXIMIZED); actionURL.setParameter("param", "ActionURL"); PortletURL renderURL = pResponse.createRenderURL(); renderURL.setPortletMode(PortletMode.HELP); renderURL.setParameter("param", "RenderURL"); [...] writer.write(actionURL.toString()); writer.write(renderURL.toString());

Portlet Preferences

● Persit the user preferences

<portlet-preferences> <preference> <name>pref</name> <value>defaultPref</value> <read-only>false</read-only> </preference></portlet-preferences>

PortletPreferences portletPreferences = actionRequest.getPreferences();portletPreferences.setValue("pref", "modifiedPref");portletPreferences.store();

Part II

Framework bridges

Bridges concepts

Portal

Portlet bridge

Framework servlet

JSF Bridge

● JSF : 6 phases● Portlet API : 2 phases

render() method

processAction() method

Redirect to the first jsp

<init-param> <name>default-view</name> <value>exo.component.UIUserProfile.class</value> </init-param> or<init-param> <name>default-view</name> <value>/jsf/profile.jsp</value> </init-param>

Part III

eXo platform architecture

Integrated Application Suite

● Integrated services but loosely coupled● Several layers

– Low level: Log, base de données, cache...– Midle level:

- Portlet container - Workflow- JCR

– Higher level: e-commerce, publishing

● 2 types of clients :• Portal channel• WSRP consumers

● Skeleton for higher level applications like CRM, ERP modules builds

IoC / Dependancy injection

● Hollywood principle : “don't call me, I will call you”● Clear distinction between the service/component

API and their implementation● Use of lightweight containers : Pico container

● Depandancy injection (Martin Fowler)

IoC 2

● How to inject the correct implementation into the objects :• Constructor injection public ServiceA(ServiceB serviceB) {...}• Setter injection public void setServiceB(ServiceB serviceB) {...}• Service locator pattern ServicesManager.getInstance().getService(ServiceB.class)

● Side effects :• Unit tests (maintainability, refactor)• Components : POJOs ( != EJBs )

The services

● LogService● CacheService● ThreadPoolService● DatabaseService/HibernateService● OrganizationService● WorkflowService● JCRService (JSR 170)● PublishingService● PortletContainerService (JSR 168)● WSRPService● ChartService● OfficeService● EcommerceService● CommunicationService● ...

The standards

● Portlet API • JSR 168 (JCP), certification, december 2003

● Web Service for Remote Portals (WSRP)• OASIS, interoperability discussions

● Java Content Repository• JSR 170, public draft in “february”

● JSR 207: Process Definition for Java

Portlet container architecture

WSRP

If You Only Remember One Thing…

Next big step : makes J2EE easier

Q&A

BeJug Workshop 2004