public static void main(String args[]) throws Exception { List<ServerAddress> addrs = new LinkedList<ServerAddress>(); addrs.add(new ServerAddress("127.0.0.1", 27017)); addrs.add(new ServerAddress("127.0.0.1", 27018)); Mongo m = new Mongo(addrs); ReplicaSetStatus status = new ReplicaSetStatus(m, addrs); System.out.println(status.ensureMaster()._addr); while (true) { System.out.println(status.ready()); if (status.ready()) { status.printStatus(); System.out.println( "master: " + status.getMaster() + "\t secondary: " + status.getASecondary()); } System.out.println("-----------------------"); Thread.sleep(5000); } }