JCycles
[frozen] A library for computing cycles in graphs or in Java code.
[This project is frozen, but has an offspring with more features: https://github.com/jeffhain/jadecy ]
JCycles provides treatments to compute cycles, or just strongly connected components, in directed graphs in general, or in classes or packages dependencies graphs parsed from class files (major version <= 51, else does best effort).
It uses Tarjan's algorithm for SCCs, and Johnson's for cycles, with continuations instead of recursion, which allows to handle large graphs