ZeroMQ - Mindgames and Samples

Router bound, 2 Dealers connected to Router


In this sample:

  • Send data from dealer1 to router
  • Create message to push data from router to dealer1 and dealer2

import java.nio.charset.Charset;

import org.junit.Test;
import org.zeromq.ZContext;
import org.zeromq.ZMQ;
import org.zeromq.ZMsg;

public class BRouterToCDealer {

	public void testmain() {
		ZContext ctx = new ZContext();

		ZMQ.Socket router = ctx.createSocket(ZMQ.ROUTER);
		// give the socket an identity. this name will be used as address if
		// this socket connects to a router.
		// this is important if you want to route to a socket that didn't
		// contact you before

		ZMQ.Socket dealer1 = ctx.createSocket(ZMQ.DEALER);
		// give the dealer an identity. here it is actually important

		ZMQ.Socket dealer2 = ctx.createSocket(ZMQ.DEALER);
		// give the dealer an identity. here it is actually important

		// send data to router
		// receive data as msg from router.
		// the router adds one frame with the address of the caller to be able
		// to send it back again
		ZMsg msg = ZMsg.recvMsg(router);
		// get that address that is added by the router
		String addressFromCaller = msg.popString();
		assert (addressFromCaller.equals("dealer1"));
		// get the actual data sent by dealer1
		String dataSentByCaller = msg.popString();
		assert (dataSentByCaller.equals("d1-data"));
		System.out.println("router got msg:" + msg);

		// send data from router to dealer1
		// stack togather:
		// first the address
		// followed by the data that should be sent to dealer1
		// the router gets the whole msg and expects the first frame to be a
		// routing-address
		// if this address is in a internal table it pops the address again and
		// sends the rest to this connection
		router.send("r1 - hi dealer1");

		// you can send as many msgs as you want (and as the router-queue can
		// handle)
		// now let's send a message to dealer2 using ZMsg
		ZMsg msgToD2 = new ZMsg();
		// here we have to stack upwards down.
		// first: the data
		msgToD2.push("r1 - hi dealer2");
		// second: the routing-address

		// now let's receive the msgs the server sent
		msg = ZMsg.recvMsg(dealer1);
		String incomingMsgD1 = msg.popString();
		assert (incomingMsgD1.equals("r1 - hi dealer1"));
		System.out.println("dealer1:" + incomingMsgD1);
		// get the data directly from the socket
		String incomingDataD2 = dealer2.recvStr(Charset.defaultCharset());
		assert (incomingDataD2.equals("r1 - hi dealer2"));
		System.out.println("dealer2:" + incomingDataD2);
		// check if there are more parts left in the msgs we are now reading
		// line by line (in our case,no)
		boolean moreData = dealer2.hasReceiveMore();
		assert (!moreData);

		// close the context