// 例子：UDP服务端

var PORT = 33333;

var HOST = '127.0.0.1';

var dgram = require('dgram');

var server = dgram.createSocket('udp4');

server.on('listening', function () {

    var address = server.address();

    console.log('UDP Server listening on ' + address.address + ":" + address.port);

});

server.on('message', function (message, remote) {

    console.log(remote.address + ':' + remote.port +' - ' + message);

});

server.bind(PORT, HOST);

// 例子：UDP客户端

var PORT = 33333;

var HOST = '127.0.0.1';

var dgram = require('dgram');

var message = Buffer.from('My KungFu is Good!');

var client = dgram.createSocket('udp4');

client.send(message, PORT, HOST, function(err, bytes) {

    if (err) throw err;

    console.log('UDP message sent to ' + HOST +':'+ PORT);

    client.close();

});

node server.js

➜  2016.12.22-dgram git:(master) ✗ node client.js

UDP message sent to 127.0.0.1:33333

UDP Server listening on 127.0.0.1:33333

127.0.0.1:58940 - My KungFu is Good!

广播

通过dgram实现广播功能很简单，服务端代码如下。

var dgram = require('dgram');

var server = dgram.createSocket('udp4');

var port = 33333;

server.on('message', function(message, rinfo){

    console.log('server got message from: ' + rinfo.address + ':' + rinfo.port);

});

server.bind(port);

接着创建客户端，向地址'255.255.255.255:33333'进行广播。

var dgram = require('dgram');

var client = dgram.createSocket('udp4');

var msg = Buffer.from('hello world');

var port = 33333;

var host = '255.255.255.255';

client.bind(function(){

    client.setBroadcast(true);

    client.send(msg, port, host, function(err){

        if(err) throw err;

        console.log('msg has been sent');

        client.close();

    });

});

运行程序，最终服务端打印日志如下

➜  2016.12.22-dgram git:(master) ✗ node broadcast-server.js

server got message from: 192.168.0.102:61010

相关链接

https://nodejs.org/api/dgram.html