GCube Portal Engine
To provide the end user with the full functionality of the gCube system, a presentation application, based on the ASL and not on the lower level gCube services directly, has been implemented.
For this application the portal/portlet paradigm has been adopted. A portal is a Web-based desktop that is customizable both in the look and feel and in the content and applications which it contains. A portal, furthermore, is an aggregator of content and applications or a single point of entry to a user's set of tools and applications. The portlets are the visual components that participate into providing the user-conceived functionality of the portal. Behind the portal there is always an engine (and a framework) that powers the system.
In gCube the GridSphere1 portal framework is employed as the portlet-hosting platform. GridSphere is an open-source framework which enables developers to develop and package third-party portlet web applications that can be run and administered within the GridSphere portlet container. For its purposes, it uses the JSR 168 Portlet API, to provide reusable web applications.
For the development of portlets several technologies are involved: the JSR 168 portlet API, Java Server Pages for dynamically generation of HTML/XML documents in response to a client’s request and GWT (Google Web Toolkit) for writing high performance AJAX applications. All these technologies are hosted under the Gridsphere Portal engine.