Portlets
Portlets are reusable web modules that provide
access to Web-based content, applications, and other resources. Portlets
can run on the application server because it has an embedded JSR 286
Portlet container. The JSR 286 API provides backwards compatibility.
You can assemble portlets into a larger portal page, with multiple
instances of the same portlet displaying different data for each user.
Portlet filters
Since the release of JSR 286: Portlet Specification 2.0,
it is possible to intercept and manipulate the request and response
before they are delivered to a portlet in a given phase. Using Portlet
filters you can block the rendering of a portlet if a specific
condition occurs. Also, you can use portlet filters to decorate a
request and a response within a wrapper to modify the behavior of
the portlet.
Portlet container
The portlet container is the runtime environment
for portlets using the JSR 286 Portlet specification, in which portlets
are instantiated, used, and finally destroyed. The JSR 286 Portlet
application programming interface (API) provides standard interfaces
for portlets and backwards compatibility for JSR 168 portlets. Portlets
that are based on this JSR 286 Portlet Specification are referred
to as standard portlets.