open-source java programs with an accessible source-code?

I'm making a research within software testing field, during the research I will be studying and analyzing a decent amount of open-source programs written in java specially! My question is where can I find a suffecintlly large projects with an accessible source-code? What I mean by suffecintlly large projects; are projects with a range of 500K lines of code and with a base user >10 000! It deos not need to be the exact number, but more or less! Also would such projects have thier source code accessible via github or some other VCS's websites?

thanks!