public void run() {
ZContext ctx = new ZContext();
Socket frontend = ctx.createSocket(ZMQ.ROUTER);
Socket backend = ctx.createSocket(ZMQ.ROUTER);
frontend.bind("tcp://*:5555");
backend.bind("tcp://*:5556");
while (!Thread.currentThread().isInterrupted()) {
ZMQ.Poller items = ctx.getContext().poller();
items.register(frontend, ZMQ.Poller.POLLIN);
items.register(backend, ZMQ.Poller.POLLIN);