How to determine which source files are required for an Eclipse run configuration

When writing code in an Eclipse project, I'm usually quite messy and undisciplined in how I create and organize my classes, at least in the early hacky and experimental stages. In particular, I create more than one class with a main method for testing different ideas that share most of the same classes.

If I come up with something like a useful app, I can export it to a runnable jar so I can share it with friends. But this simply packs up the whole project, which can become several megabytes big if I'm relying on large library such as httpclient.

Also, if I decide to refactor my lump of code into several projects once I work out what works, and I can't remember which source files are used in a particular run configuration, all I can do it copy the main class to a new project and then keep copying missing types till the new project compiles.

Is there a way in Eclipse to determine which classes are actually used in a particular run configuration?

EDIT: Here's an example. Say I'm experimenting with web scraping, and so 开发者_JAVA技巧far I've tried to scrape the search-result pages of both youtube.com and wrzuta.pl. I have a bunch of classes that implement scraping in general, a few that are specific to each of youtube and wrzuta. On top of this I have a basic gui common to both scrapers, but a few wrzuta- and youtube-specific buttons and options.

The WrzutaGuiMain and YoutubeGuiMain classes each contain a main method to configure and show the gui for each respective website. Can Eclipse look at each of these to determine which types are referenced?

Take a look at ProGuard, it is a "java shrinker, optimizer, obfuscator, and preverifier". I think you'll mainly be interested in the first capability for this problem.

Yes it's not technically part of Eclipse, as you requested, but it can be run from an Ant script, which can be pretty easily run in Eclipse.

I create more than one class with a main method for testing different ideas that share most of the same classes.

It's better to be pedantic than lazy, it saves you time when coding :-) You can have one class with a main method that accepts a command-line argument and calls a certain branch of functionality based on its value.