Advice for mapping an undocumented Java Eclipse Project

I have started at a new firm and as part of my duti开发者_StackOverflow社区es am making small changes on a Java Project that was developed previously. The problem is that it is mostly undocumented and very complex. By undocumented I mean no comments, no Java doc, no documentation guide, nothing. It's a website Java project developed in Eclipse and built using Ant. My question is what tools are available to help me map out the project to better understand it. Or is there any advice on the best set of steps to follow.

Thank you for your time.

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Look into reverse engineering tools that can create UML diagrams for java, like omondo. If the ant build script is complex aswell - I once visualized some complex ant build script using yEd, that helped a lot.

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I personally found that UML-based tools do not scale well in such cases, except for some very specific cases, where sequence diagrams might help a lot.

Instead, I would refer to the following book (available online) for a general approach to the problem:

http://scg.unibe.ch/download/oorp/

And try out some research tools for code visualization to get an overview, for example:

http://www.inf.usi.ch/faculty/lanza/codecrawler.html

(would love to post more links, but can't due to stackoverflow's spam prevention mechanism)