为什么我不能创建从 Android 设备到 PC 的 tcp 套接字

Question

I'm trying to connect my Android app to desktop server. The problem is when I try to create LAN via portable Wi-Fi hotspot on my smartphone everything works fine, but when I connect PC and phone to the router I have TimeOutException creating a socket in Android app. On the other hand, when I connect desktop client to desktop server via router it works fine too, so the problem occures only when I try to connect mobile client to desktop server via router.

Client code (Java):

Socket socket = new Socket();
socket.connect(new InetSocketAddress(ip, port), 1000); // TimeOutException

Server code (C++/Qt):

QTcpServer m_tcp_server;
// ...
m_tcp_server->listen(QHostAddress::Any, m_port);

ip address and port are right (100%)

UPD:

Thank you, guys.

It was just a router problem. I tested in on the another one and there is no problem

Answer 1

try check which ip you have assigned on android pohone and if you have route to the destination server ip.

Is possilbe you get different ip on wifi and different ip by cable.

Also you can try an android net tool to try connect to the server.

Answer 2

I had same problem, In my case i created server socket with wrong ip address. Hotspot network band is 192.168.43.1~255

You need to create server socket with ip address that hotspot dhcp made like 192.168.43.11

I had wrongfully made server socket with ip 192.168.0.22, this is wrong.

And your android app should open client socket with it.