javascript - Why does my Node.js script not see any UDP packets that are being sent on a specific port? -


i have c# app sends udp packets specific ip , port , works well, because have other app receives packages. send them can display on webpage - i've read node.js fit here.

i installed current version of node.js under windows environment , took following code:

var port            = 19777; var multicast_group = "224.0.0.251";  var dgram = require("dgram");  var client = dgram.createsocket("udp4");  client.on("message", function(message, rinfo) {     console.log("received: ",message,rinfo); }); client.on("listening", function() {     console.log("listening on ",client.address());      client.setbroadcast(true);     client.setttl(64);     client.setmulticastttl(64);     client.setmulticastloopback(true);     client.addmembership(multicast_group);     client.send(payload, 0, payload.length, port, multicast_group, function(err,bytes) {         console.log("err: "+err+" bytes: "+bytes);         // client.close();     }); }); client.on("close", function() {     console.log("closed"); }); client.on("error", function(err) {     console.log("error: ",err); }); client.bind(19777);

and started sending packets on following ip "224.0.0.251" , port 19777 c# app - however, after runnint client app i've got following error:

c:\users\user\desktop>node client.js error:  { [error: bind eaddrinuse] code: 'eaddrinuse', errno: 'eaddrinuse', sysc all: 'bind' }

what doing wrong? , - after fixing issue - able see packets in console? thanks.

------------- edit:

following advice of john, modified app node.js listening on port. made progress , on output of console get:

c:\users\user\desktop>node client.js listening on  { address: '0.0.0.0', family: 'ipv4', port: 19777 } c:\users\user\desktop\client.js:19     client.send(payload, 0, payload.length, port, multicast_group, function(er                 ^ referenceerror: payload not defined     @ socket.<anonymous> (c:\users\godyckim\desktop\client.js:19:17)     @ socket.emit (events.js:104:17)     @ startlistening (dgram.js:139:10)     @ dgram.js:230:7     @ dns.js:85:18     @ process._tickcallback (node.js:355:11)     @ function.module.runmain (module.js:503:11)     @ startup (node.js:129:16)     @ node.js:814:3

but still no packets visible.. ok, see didn't define payload variable... want achieve receive packets sent udp , either display in node.js console (that start me), or transfer further can see them in browser. in second case - i'm doing wrong now? thanks!


Comments

Post a Comment

Popular posts from this blog

php - failed to open stream: HTTP request failed! HTTP/1.0 400 Bad Request -

this code i'm using find latitude , longitude of place: function coords($address){ echo $url="http://maps.googleapis.com/maps/api/geocode/json?address=".$address; $json = file_get_contents(urlencode($url)); $data = json_decode($json, true); print_r($data['results'][0]['geometry']['location']['lat']); print_r($data['results'][0]['geometry']['location']['lng']); } however returns warning: failed open stream: http request failed! http/1.0 400 bad request if use above code in simple procedure works fine not in function. note: have tried curl_init()... method produced same result? instead of encoding whole url encode address part. following code work fine $add='jamshoro phase 2'; $url="http://maps.googleapis.com/maps/api/geocode/json?address=".urlencode($add); $json = file_get_contents($url); $data = json_decode($json, true); print_r($data['r
Read more

java - How to filter a backspace keyboard input -

i have code gives message when key number pressed: txtvalueofclause.addeventfilter(keyevent.key_typed, new eventhandler<keyevent>() { @override public void handle(keyevent t) { char ar[] = t.getcharacter().tochararray(); char ch = ar[t.getcharacter().tochararray().length - 1]; if (!(ch >= '0' && ch <= '9')) { system.out.println("the char entered not number"); t.consume(); } } }); now if press on wrong button , press backspace remove it, error message. how can add backspace input if statement? i have found answer: txtvalueofclause.addeventfilter(keyevent.key_typed, new eventhandler<keyevent>() { @override public void handle(keyevent t) { char ar[] = t.getcharacter().tochararray(); char ch = ar[t.getcharacter().tochar
Read more

java - Show Soft Keyboard when EditText Appears -

i have code in android app, alert dialog , keyboard, , when dialog shown want keyboard appear. not , not sure why? here code: final alertdialog.builder alert = new alertdialog.builder(this); alert.settitle("title"); alert.setmessage("message"); final edittext input = new edittext(this); input.setinputtype(inputtype.type_class_number); alert.setview(input); input.setonfocuschangelistener(new view.onfocuschangelistener() { @override public void onfocuschange(view v, boolean hasfocus) { if (hasfocus) { log.i(tag, "in focus"); inputmethodmanager inputmethodmanager = (inputmethodmanager) getsystemservice(context.input_method_service); inputmethodmanager.showsoftinput(input, inputmethodmanager.show_implicit); } } }); but keyboard not appear though edit text in focus, , tell appear why, doesn't come up? thanks in advance.
Read more