UDP library

Provides functionality for UDP communication. This library provides only client functionality.

This library can be initialized

var Udp = require('udp');

Create UDP instantion

udp = new Udp(1024);

Constructor creates new instance of Udp object with max. 1024 bytes datagram space. For one UDP connection you need one instance.

Prepare UDP datagram

Datagram newDatagram(size)

Number size - contains size of new datagram;

Returns instance of Datagram.

Set data into datagram

Datagram.setData(data)

ByteBuffer data - contains data which will be sent

Set address into datagram

Datagram.setAddress(address)

String address

Get data from datagram

ByteBuffer Datagram.getData()

Returns contained data as ByteBuffer object.

Get address from datagram

String Datagram.getAddress();

Returns address from instance of Datagram.

Open UDP connection

open(address,callback(error_code));

String address - address in format ip_or_domain_name:port_number

Function callback - function will be invoked after UDP connection init.

Close UDP connection

close()

UDP example

var sys = require('system');
var Udp = require('udp');

var udp = new Udp(1024);

var sendData = function(){
    var datagram = udp.newDatagram(4);
    var b = new ByteBuffer(4);

    b.setSize(8);
    b.fillFromString("message!");
    datagram.setData(b);
    udp.send(datagram, function(err){
        sys.println("callback after send "+err);
    });
}

var openConn = function(){
    udp.open('misha.alarex.net:3002', function(err){
        if (err) {
            sys.println('Open UDP error:'+err);
            sys.setTimeout(openConn,1000);
        } else {
            sendData();
        }
    });
}

udp.udpReceived = function(datagram){
    sys.println("datagram from address:"+datagram.getAddress());
    var bb = datagram.getData();
    sys.println("received data:");
    sys.println(bb.toString());
}

openConn();

Udp library