Question: Does such program exist?

I have to study Java SE and diagram with all classes and interfaces from given package will be immensely helpful.

For example I want to plot all relations between subclasses of types Collection and Map.

I know there are a lot of images with core package structure already, but don't really trust them because they are proven to be incomplete, outdated or even inaccurate.

Answer: 
Whilst I don't know of any tools for generating UML class diagrams from JavaDocs, there are many tools available that can generate UML class diagrams from source code, and there are already many [questions on StackOverflow](https://stackoverflow.com/search?q=generate%20uml%20class%20diagram%20from%20java%20code) that suggest various tools that can do this

[This question](https://stackoverflow.com/questions/1687323/from-java-code-to-uml-diagram) seems to have a good range of options that you could explore. I've used [ArgoUML](http://argouml.tigris.org/) myself, but I suggest looking at the options to find the one what appeals to you most.

You can download the [Java SE source code](http://download.java.net/jdk6/source/) and generate the class diagrams for the sections you're interested in.
You can create RCP application using [ZEST](http://eclipse.org/gef/zest). This is pretty cool