SOA architecture and Web services as its implementation technology has been widely adopted across industries for exposing applications as services as well as a future technology to develop new services . These services are either consumed by other applications or exposed to end-users through portal applications (or other user interfaces). Broadly, portals are regarded as one-point access to all applications a consume needs. Often, a portal is aggregation of pluggable UI fragments called portlets. Portlets are interactive Web applications that aggregate data from local or remote applications/services and displayed by portals. These portlets are often complex and hard to design, sit locally on system and are particular to the portal container. This marrs the dynamic integration of business applications and information resources into portals, which would often require redesign of portlets for each particular service consumed. By integrating these portlets (i.e. the presentation logic) with corresponding services (i.e. the application), often called Remote Portlets, the extra burden of portlet management can be avoided.
Web Services for Remote Portlets (WSRP), which evolved from JSR 168 provides standards for interaction with presentation-oriented Web services and expose remote portlets as services. WSRP-compliant portals consume these services. It standardizes the interface definitions in service interactions between various user interface components, even taking into consideration the run-time user interactions with those components.
In this view, we have analyzed various offerings for WSRP from key players in the market. Following salient parameters were chosen for comparison:-
- Session Management: In communications between portlets, between browser sessions and inter portlet communications.
- Markup Generation and use.
- Security: Supported standards and its integration with portal application.
- Interoperability: Between portal and different technologies.
- Customization: To what extent and difficulties in customisation.
|Parameters||Weblogic Portal 8.1 SP3||WebSphere Portal 5.1||MS SharePoint Portal Server 2003||Sun ONE Portal Server|
|Session Management||The Producer-Consumer session is tied to the user session.||Session data is lost for each request. An additional request to the Producer is submitted to establish a session.||Allows Web Parts to interchange information and objects within a browser session.||HTTP Session easily configurable.|
|Markup Generation||URLs may be written by the Producer or the Consumer. Consumer supplies URL templates for producer rewriting. Producer inserts markers in the markup for Consumer rewriting.||Submitting data to a portlet through forms changes state of the portlet. It prevents the submission of form data through render requests. Portlets that use render URLs to submit form data don't work remotely.||SharePoint Products and Technologies now use Web Part Pages and Web Parts based on the .NET Framework and ASP.NET.||Applets and frames|
|Security||Although, Weblogic supports various open standards, WSRP security is not that well matured.||Complies with the JSR-109 standard, can use WS-security features. WSRP Consumer and Producer can be configured to use Lightweight Third-Party Authentication (LTPA) . The WSRP Portal may configure Secure Socket Layer (SSL) with Client Certificate Authentication.||Uses Windows authentication or Web-based authentication depending on the user registration. Single sign on.||Uses Secure Remote Access to provide highly secure remote access portals. Single sign on.|
|Interoperability||Tested with Consumers that use IBM, Oracle and Citrix producers.||Tested with numerous Consumers.||WSRP-complaint Web parts deployable.||Tested with numerous Consumers.|
|Customization||The settings like WSRP SOAP Ports, Proxy Settings not easily customizable.||The WSRP SOAP Ports, Proxy Settings, Parallel Port Rendering, Switching Catching Off and On easily configurable.||Provides own custom style sheet.||Provides good customization facilities.|
Application integration is major issue for enterprise portal projects. WSRP standard enables development of interoperable portlets on different portal products thereby increasing the scalability, reliability, performance and availability of portlets to an organization. This along with the advantage of user dependent selectivity and aggregation of information from all kinds of sources can dramatically increase reach and productivity when building enterprise portals. Without WSRP, organizations are limited to propriety portlet technology that not only locks it to a particular vendor, but also increases the development and deployment time for front-end applications that talk to standardized Web services at the back end.