JSR 168 portlet specification standard
Java Standardization Request 168 (JSR 168) defines a portlet specification, including contracts between portlet containers and portlets. JSR 168 is defined by Java Community Process (JCP). JSR 168 is commonly led by IBM and Sun, and has a large Expect group to help create the final version currently available. This expert group consists of Apache Software Foundation, Art Technology Group Inc. (ATG), BEA, BOEING, BORLAND, CITRIX SYSTEMS, Fujitsu, Hitachi, IBM, Novell, Oracle, SAP, SAS INSTIS, Sun, Sybase, Tibco, and Vignette.
More information about JSR can be found on http://jcp.org/en/jsr/detail?id=168.
Portal and Portlet containers
Portal is a web application that typically provides personalization of different sources, single-point login content collections, and hosts representations of different backend systems. The main task of Portal is to set different applications to a page, the appearance of this page is Portal users. Portal also has complex personalized features that provide users with custom content. Portal page can have different portlet sets to create content for different users.
The client request is processed by the Portal web application, which retrieves the Portlet on the current page for the current user. The Portal web application then calls the portlet container for each portlet to retrieve its content via the Container Invoker API. The portlet container calls the portlet via the portlet API. Container Provider Service Provider Interface (SPI) allows the portl to retrieve information through Portal.
Figure 3. Basic Portal architecture
Portal page and portlet
The basic Portal page assembly is displayed. Portal page represents a complete tag document and aggregates several portlet windows; that is, it combines different application user interface to a unified representation. Portal page enables users to verify their identity to Portal via the login dialog box to access personalized Portal views. Most Portal pages include some navigation mechanisms to allow users to navigate to other portal pages.
The portlet window includes:
l Title Bar with the title of portlet
l Modification, including buttons (such as maximizing or minimizing portlet) for changing portlets, buttons for changing the mode of the portlet (such as display help or editing a predefined portlet setting)
l The content generated by the portlet (also known as a tag).
A portlet window is displayed on a different browser. As you can see, the portlet generated by the portlet is not limited to HTML, but can be any tag.
