SocketException: OS Error: Connection refused, errno = 111

I encountered a peculiar error while developing a Flutter app on Windows. I had configured my local Apache server as the API server. When I tested the API using Postman, everything worked fine. However, the error surfaced when I tested the API within the app using an emulator.

As it turns out, the problem was with the emulator itself. Android emulators cannot communicate with 127.0.0.1 or localhost. The solution was straightforward: I replaced localhost with 10.0.2.2. This IP address serves as a special alias to your host loopback interface.

For more details, you can refer to this docs