simple server/client example

is there some simple client/server example? i did not find one. i am currently trying to get the basics working.

import org.zeromq.ZContext;
import org.zeromq.ZMQ;

public class Server {

    ZContext context = new ZContext(1);
    ZMQ.Socket socket = context.createSocket(ZMQ.PAIR);

    public static void main(String args[]) {
        Server server = new Server();
        server.start();

    }

    public void start() {

        // Socket to talk to clients
        socket.bind("tcp://*:10101");
        byte[] recv = socket.recv();
        System.out.println("Received " + new String(recv));
    }

    public void stop() {
        socket.close();
        context.close();
    }
}

import org.zeromq.ZContext;
import org.zeromq.ZMQ;

public class Client {

    ZContext context = new ZContext(1);
    ZMQ.Socket socket = context.createSocket(ZMQ.PAIR);

    public void sendMessage() {
        socket.connect("tcp://127.0.0.1:10101");
//        byte[] recv = socket.recv();
//        if (recv != null) {
//            System.out.println("received: " + new String(recv));
//        }
        boolean b =  socket.send("hi");
        System.out.println("Sent with return: " + b);
    }

    public static void main(String args[]) {
        Client client = new Client();
        client.sendMessage();
    }

}

Can someone tell me why this is not working? The client sends the data and “b” is true, so i assume it is sent. But the server never receives it.

[damnms]

thanks, i understood that 😉

[fredoboulo]

Hi, I noticed you did not close the context of the client and did not set linger of the socket to -1.

The meaning of send() true is more like “Ok, I queued the message and will make best efforts to actually send it”.

As the client is stopped straight after queuing the message, this message might not have processed by the I/O thread.

Closing the context with linger -1 will block until all pending messages have been sent to a peer.