UDP Server Notes in Nodejs

1.js

var dgram = require('dgram');


var UDPServer = function() {
};

UDPServer.prototype.createServer = function(msgCallback) {
  var sock = dgram.createSocket('udp4');
  this.sock = sock;
  sock.on('message', function(msg, rinfo){ 
    msgCallback(this, msg, rinfo);
  });
};

UDPServer.prototype.close = function() {
  this.sock.close();
};

UDPServer.prototype.listen = function(host, port, cb) {
  if(arguments.length < 3) {
    this.sock.bind(host, port);
  } else {
    this.sock.bind(host, port, function(){
      cb();
    });
  }
};

var srv = new UDPServer();
srv.createServer(function(sock, message, rinfo){
  console.log(message.toString());
  console.log(JSON.stringify(rinfo));
  sock.send(message, 0, message.length, rinfo.port, rinfo.address, function(err, bytes) {
    if(err) {
      console.log(arguments);
    } else {
      console.log("sent");
    }
  });
});

srv.listen(3000, function() {
  console.log("Bound to port 3000");
});