Java Portlet Specification

The Java Portlet Specification defines a contract between a portlet and its container; it provides a convenient programming model for Java portlet developers. Multiple versions of the specification, each a Java Specification Request (JSR) document, have been released with each intended to define an improved technology compared to the previous version.

A Java portlet resembles a Java servlet but produces fragments rather than complete documents, and is not bound by a URL.

"JSR 286: Portlet Specification 2.0".

↑ "JSR 362: Portlet Specification 3.0".

↑