Unable to connect to websocket server on Android QML App

PaulGrant

Hi,
I've taken the basic websocket server example from qt5.9, place it in a android project
and tried to connect to it from a linux based websocket client, but it refuses to accept
a connection. I see the error in the node console.
The same app will accept connection if run as a linux desktop app?!?

On Android i'm using APK19.

To test if websockets can work in this way on android I've downloaded an
app from the android store and found I can connect to it fine!

I checked permissions on the app and found the following:
ACCESS_NETWORK_STATE
ACCESS_WIFI_STATE
CHANGE_NETWORK_STATE
CHANGE_WIFI_STATE
INTERNET
I've added these to the android app, but it still refuses to accept connection!

Is there a separate permission required for QT/QML network access?
What would cause this?

Any help would be appreciated!
BR
Paul Grant

jsulm

@PaulGrant said in Unable to connect to websocket server on Android QML App:

I see the error in the node console

What is the error?

PaulGrant

HI, error is connection refused, which seems to imply permissions issue!

Error: connect ECONNREFUSED 192.168.1.141:8003
at Object.exports._errnoException (util.js:870:11)
at exports._exceptionWithHostPort (util.js:893:20)
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1063:14)

Additionally if I creat a websocket client in same QML it can communicate
with the server, even when I change the IP of the server from localhost which is
default to actual IP of android device. This again seems to imply a permissions issue!?!

But I dont know of any other relavent Android permissions

BR, Paul

jsulm

@PaulGrant I'm not an Android expert, but I can imagine that Android does not allow connections from outside of the device for security reasons.
Why would you want to have a server on your phone?

mrjj

Hi
Im no expert either but fooling around with my old one and trying stuff i had to root it to connect to it
https://www.digitaltrends.com/mobile/how-to-make-an-android-server/

raven-worx

@PaulGrant
i am also not an android expert :P
But following points come to my mind:

are you sure your web-socket server listens on port 8003?
do you let your websocket server listen on QHostAddress::Any network address/interface?
maybe you can try to launch the server only as soon as a network/WiFi connection is available?

the most important permission is the INTERNET permission, since this lets you open network sockets.

aneh

You can use OKHTTP3 WebSocket which is really very easy to configure in android you can try this post: https://trinitytuts.com/connect-to-websocket-on-android-using-okhttp/