There are also plethora of use-cases for such a solution.
The idea is to have a comprehensive representation of the JSP in EMF. The level of abstraction is the same, but in a format (EMF) which allows using and combining any EMF compliant tool (browsing, mode-to-model transformation, code generation, comparison, ...).
For example, for one of our customers who had a Struts based application which was not documented at all, we have used EMF models of the JSP pages, the Java classes and the struts-config.xml file to deduce a UML model (with a specific profile) describing the cinematic of the application (pages, actions, forms, events, ...). This UML model has been created with Mia-Studio which is a model-to-model transformation tool based on EMF. The transformation rules were specific to the patterns which have been used by this customer.
We could also use a model of JSP to check coding norms or design patterns.
We can also perform a transformation directly on the JSP model and then regenerate the JSP file. It allows performing refactorings on existing JSPs.
Due to the plethora of frameworks and specific practices, you will never find the tool which does exactly what you want. So, our objective is to provide a solution which facilitates the development of specific tools dedicated to the context of your project(s).