How to learn from Javadoc

Given a large (third-party) library with hundreds of classes and interfaces, I find it difficult to follow Javadoc:

The goal is to find out the differences and understand what the class / interface does / doesn't do so that the library can be used correctly and effectively

Is there a tool that uses Javadoc of a given class / interface to generate its hierarchy diagram and compare / compare the differences between children and their parents / grandparents / siblings?

Of course, this can be done manually, but it takes time each time Is there a more effective way to do this? thank you.

Editor: – I should add that I have no access to the source code of the library. – This library is given in a jar of Javadoc with literal wording (just class / interface / method signature, some meaningful names and some descriptions)

Solution

Yes, you can create a class diagram through reverse engineering This is a tutorial on reverse engineering source code for generating UML diagrams: http://java.dzone.com/articles/reverse-engineer-source-code-u