Clone server, Model Four in Java

import org.zeromq.ZContext;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Poller;
import org.zeromq.ZMQ.Socket;

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

/**
* Clone server Model Four
*/

public class clonesrv4
{
private static Map<String, kvsimple> kvMap = new LinkedHashMap<String, kvsimple>();

public void run() {

ZContext ctx = new ZContext();

Socket snapshot = ctx.createSocket(ZMQ.ROUTER);
snapshot.bind("tcp://*:5556");

Socket publisher = ctx.createSocket(ZMQ.PUB);
publisher.bind("tcp://*:5557");

Socket collector = ctx.createSocket(ZMQ.PULL);
collector.bind("tcp://*:5558");

Poller poller = new Poller(2);
poller.register(collector, Poller.POLLIN);
poller.register(snapshot, Poller.POLLIN);

long sequence = 0;
while (!Thread.currentThread().isInterrupted()) {
if (poller.poll(1000) < 0)
break; // Context has been shut down

// apply state updates from main thread
if (poller.pollin(0)) {
kvsimple kvMsg = kvsimple.recv(collector);
if (kvMsg == null) // Interrupted
break;
kvMsg.setSequence(++sequence);
kvMsg.send(publisher);
clonesrv4.kvMap.put(kvMsg.getKey(), kvMsg);
System.out.printf("I: publishing update %5d\n", sequence);
}

// execute state snapshot request
if (poller.pollin(1)) {
byte[] identity = snapshot.recv(0);
if (identity == null)
break; // Interrupted

// Request is in second frame of message
String request = snapshot.recvStr();

if (!request.equals("ICANHAZ?")) {
System.out.println("E: bad request, aborting");
break;
}

String subtree = snapshot.recvStr();

Iterator<Entry<String, kvsimple>> iter = kvMap.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, kvsimple> entry = iter.next();
kvsimple msg = entry.getValue();
System.out.println("Sending message " + entry.getValue().getSequence());
this.sendMessage(msg, identity, subtree, snapshot);
}

// now send end message with sequence number
System.out.println("Sending state snapshot = " + sequence);
snapshot.send(identity, ZMQ.SNDMORE);
kvsimple message = new kvsimple("KTHXBAI", sequence, "".getBytes());
message.send(snapshot);
}
}
System.out.printf (" Interrupted\n%d messages handled\n", sequence);
ctx.destroy();
}

private void sendMessage(kvsimple msg, byte[] identity, String subtree, Socket snapshot) {
snapshot.send(identity, ZMQ.SNDMORE);
snapshot.send(subtree, ZMQ.SNDMORE);
msg.send(snapshot);
}

public static void main(String[] args) {
new clonesrv4().run();
}
}