protected String getWorkerMain(SimpleVersion topoVersion) { String defaultWorkerGuess = "org.apache.storm.daemon.worker.Worker"; if (topoVersion.getMajor() == 0) { //Prior to the org.apache change defaultWorkerGuess = "backtype.storm.daemon.worker"; } else if (topoVersion.getMajor() == 1) { //Have not moved to a java worker yet defaultWorkerGuess = "org.apache.storm.daemon.worker"; } NavigableMap<SimpleVersion, String> mains = Utils.getConfiguredWorkerMainVersions(_conf); return Utils.getCompatibleVersion(mains, topoVersion, "worker main class", defaultWorkerGuess); }