// Find the root thread group ThreadGroup root = Thread.currentThread().getThreadGroup().getParent(); while (root.getParent() != null) { root = root.getParent(); } // Visit each thread group visit(root, 0); // This method recursively visits all thread groups under `group'. public static void visit(ThreadGroup group, int level) { // Get threads in `group' int numThreads = group.activeCount(); Thread[] threads = new Thread[numThreads*2]; numThreads = group.enumerate(threads, false); // Enumerate each thread in `group' for (int i=0; i<numThreads; i++) { // Get thread Thread thread = threads[i]; } // Get thread subgroups of `group' int numGroups = group.activeGroupCount(); ThreadGroup[] groups = new ThreadGroup[numGroups*2]; numGroups = group.enumerate(groups, false); // Recursively visit each subgroup for (int i=0; i<numGroups; i++) { visit(groups[i], level+1); } }