Question

I’m trying to get a PC client to connect to an Android server. This is running in the emulator. I cannot get the PC client to connect.

The android server..

try {
        serverSocket = new ServerSocket( 1234 );

        //tell logcat the server is online
        Log.d("TCP", "C: Server Online...");

        while ( true ) {
            Log.d("TCP", "C: Waiting for client" );

            Socket client = serverSocket.accept();

            Log.d("TCP", "C: Client has connected" );

            BufferedReader in = new BufferedReader(
                    new InputStreamReader( 
                            client.getInputStream() ) );
            String input = in.readLine();

            Log.d("TCP", "C: " + input );

            client.close();
        }
    } catch ( Exception e ) {
        Log.d( "TCP", "C: " + e );
    }

and the PC client

String host = "127.0.0.1";

//Port the server is running on.
int port = 1234;

//Message to be sent to the PC
String message = "Hello from  pc.";
//Get the address of the host.
InetAddress remoteAddr = InetAddress.getByName( host );

//Tell the user that we are attempting a connect.
System.out.println("Attempting connect");

//Make the connection
Socket socket = new Socket(host, port);

//Tell user the connection was established
System.out.println("Connection made");

//Make the output stream to send the data.
OutputStream output = socket.getOutputStream();
PrintWriter out = new PrintWriter(new BufferedWriter(
    new OutputStreamWriter(output)), true);

//Send the data.
out.println(message);

//Tell user the message was sent
System.out.println("Message sent");

I keep getting the message connection refused on the PC.. Can anyone help me with this? Cheers

Answer 1

From the docs for Emulator Networking…

The virtual router for each instance manages the 10.0.2/24 network address space

Most importantly, the emulated device’s own network address is 10.0.2.15.

I don’t use the emulator but as far as I can tell you need to setup a redirection from 127.0.0.1:<host-port> to 10.0.2.15:<guest-port>. See the docs for Setting up Redirections through the Emulator Console.

As I said, I don’t use the emulator but this is how I understand things work.