Lazy Pirate client in Java

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

//
// Lazy Pirate client
// Use zmq_poll to do a safe request-reply
// To run, start lpserver and then randomly kill/restart it
//

public class lpclient
{

private final static int REQUEST_TIMEOUT = 2500; // msecs, (> 1000!)
private final static int REQUEST_RETRIES = 3; // Before we abandon
private final static String SERVER_ENDPOINT = "tcp://localhost:5555";

public static void main(String[] argv)
{
ZContext ctx = new ZContext();
System.out.println("I: connecting to server");
Socket client = ctx.createSocket(ZMQ.REQ);
assert (client != null);
client.connect(SERVER_ENDPOINT);

int sequence = 0;
int retriesLeft = REQUEST_RETRIES;
while (retriesLeft > 0 && !Thread.currentThread().isInterrupted()) {
// We send a request, then we work to get a reply
String request = String.format("%d", ++sequence);
client.send(request);

int expect_reply = 1;
while (expect_reply > 0) {
// Poll socket for a reply, with timeout
PollItem items[] = {new PollItem(client, Poller.POLLIN)};
int rc = ZMQ.poll(items, REQUEST_TIMEOUT);
if (rc == -1)
break; // Interrupted

// Here we process a server reply and exit our loop if the
// reply is valid. If we didn't a reply we close the client
// socket and resend the request. We try a number of times
// before finally abandoning:

if (items[0].isReadable()) {
// We got a reply from the server, must match sequence
String reply = client.recvStr();
if (reply == null)
break; // Interrupted
if (Integer.parseInt(reply) == sequence) {
System.out.printf("I: server replied OK (%s)\n", reply);
retriesLeft = REQUEST_RETRIES;
expect_reply = 0;
} else
System.out.printf("E: malformed reply from server: %s\n",
reply);

} else if (--retriesLeft == 0) {
System.out.println("E: server seems to be offline, abandoning\n");
break;
} else {
System.out.println("W: no response from server, retrying\n");
// Old socket is confused; close it and open a new one
ctx.destroySocket(client);
System.out.println("I: reconnecting to server\n");
client = ctx.createSocket(ZMQ.REQ);
client.connect(SERVER_ENDPOINT);
// Send request again, on new socket
client.send(request);
}
}
}
ctx.destroy();
}
}