JSR 168 Overview

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Overview

This PowerPoint will give you an overview of JSR 168 and explain the benefits of using a JSR 168 compliant portal

It covers the portlet lifecycle and the characteristics of a portlet

The intended audience is Java developers

Objectives

What is JSR 168? What is a Portlet? Portlet Lifecycle Portlet Modes Window States Portlet Preferences Benefits of JSR 168 Final Thoughts

What is JSR 168?

JSR 168 is the Portlet Specification It was created out of a need to have a

specification for displaying multiple applications on the same page

JSR 168 defines the lifecycle of a portlet as well as its characteristics

What is a Portlet?

A portlet is a web component that processes requests and generates dynamic content

The content generated by a portlet is also called a fragment (e.g. HTML, XHTML, WML) and can be aggregated with other fragments to form a complete document

Java Portlet Specification, version 1.0. PLT.2.2

What is a Portlet?

Portlets are fragments of an html page

Portlet Lifecycle

Portlets are different from servlets in that they have a 2 phase commit

With servlets, the service() method processes all requests

With portlets, the processAction() method processes the requests and the render() method draws the contents of the portlet on the page

Portlet Lifecycle

init() Initializes the portlet

processAction() Called when the user submits a form

render() Renders the content

destroy() Cleans up the portlet

Portlet Characteristics

Portlets have additional characteristics that make them different from Servlets

Portlet Modes Window States Portlet Preferences

Some people advocate the use of IFrames instead of portlets, but IFrames cannot save stateThey also cannot communicate with the portal or any other components on the page

Portlet Modes

Each portlet has a current mode, which indicates the function the portlet is performing

All JSR 168 compliant portals must support the View, Edit and Help modes

Introduction to JSR 168—The Java Portlet Specification P3 http://developers.sun.com/portalserver/reference/techart/jsr168/pb_whitepaper.pdf

Window States

Window states indicate the amount of portal page space that will be assigned to a portlet

All JSR 168 compliant portals must support the minimized, maximized and normal window states

Introduction to JSR 168—The Java Portlet Specification P3 http://developers.sun.com/portalserver/reference/techart/jsr168/pb_whitepaper.pdf

Portlet Preferences

Portlets can be configured to provide a custom view or behavior for different users

For example, a weather portlet can show the temperature in Chicago for one user and the temperature in LA for another user

These configurations are represented as a persistent set of name-value pairs and are referred to as portlet preferencesIntroduction to JSR 168—The Java Portlet Specification P3 http://developers.sun.com/portalserver/reference/techart/jsr168/pb_whitepaper.pdf

Why Should I Use a JSR 168 Compliant Portal?

Even though flexibility and the ability to incorporate the latest technology is important, it is equally important to be based on industry standards

You don’t want to re-learn the servlet specification every time you switch servers

Similarly, you shouldn’t have to re-learn the portlet specification if you decide to switch portals

Benefits of JSR 168

Core Architecture The core architecture will be the same

across JSR 168 compliant portals For example, you can rely on the fact that

a portlet will call processAction() to process a request and then call render() to draw its contents

Benefits of JSR 168

Documentation The Portlet Specification will not change,

and you can always look to it as a source of reliable information

Standard Portlet API Developers can create one set of JSR 168

compliant portlets that can be deployed on any JSR 168 compliant portal

Final Thoughts

Portlets are becoming increasingly important as the demand increases for aggregated content

Just as JSR 154 is the de facto standard for servlets, JSR 168 sets the standard for portlets

Final Thoughts

All of the major vendors including BEA Weblogic Portal, IBM WebSphere Portal, Oracle Portal and SunOne Portal adhere to the JSR 168 specification

Any knowledge that you gain regarding the JSR 168 specification will be applicable to almost any commercial or open source portal available today

References

Java Portlet Specification http://jcp.org/aboutJava/

communityprocess/final/jsr168/

Introduction to JSR 168 http://developers.sun.com/prodtech/

portalserver/reference/techart/jsr168/pb_whitepaper.pdf

Revision History01/17/07 James Min Author

03/24/07 Ed Shin Co-Author