How to open socket over wifi given an SSID

Question

I want to open a connection over Wi-Fi. My current code is:

WifiConfiguration wifiConfig = new WifiConfiguration();
wifiConfig.SSID = String.format("\"%s\"", "MY_SSID");
wifiConfig.preSharedKey = String.format("\"%s\"", "MY_PASSWORD");

int netId = wifiManager.addNetwork(wifiConfig);
if (netId != -1 ) {
     wifiManager.enableNetwork(netId, true);
}

enableNetwork returns true which means the operation is successful. I'm not sure what to do next though.

My goal is to open a socket where I can do custom I/O over the network I have just connected to. How can I open a socket with this network? Also, how can I make sure that I actually connected to the network (is there a BroadcastReceiver I can setup)?

Any links or documentation would be awesome, I'm not sure what to search online

Answer 1

You must run a server on first device with any port you like, I'm trying 9000 in this example:

try {
    log("Waiting for client...");

    ServerSocket serverSocket = new ServerSocket(9000);
    socket = serverSocket.accept();

    log("A new client Connected!");
} catch (IOException e) {}

then search for this server on the other device on port 9000. in this example would be:

for (int i = 1; i <= 255; i++) {
    String ip = range + i;
    try {
        log("Try IP: " + ip);
        socket = new Socket();
        socket.connect(new InetSocketAddress(ip, 9000), 10);

        log("Connected!");
        return true;
    } catch (Exception e) {}
}

if you have the server ip you don't need loop. and for a simple chat you we must open an inputstream and outputstream like this:

try {
    outputStream = new DataOutputStream(socket.getOutputStream());
    inputStream = new BufferedReader(new InputStreamReader(socket.getInputStream()));
} catch (IOException e1) {
    log("Error: Connection is not stable, exit");
    shutdown();
}

while (true) {
    try {
        String message = inputStream.readLine();
        if (message != null) {
            log(message);
        }
    } catch (IOException e) {}
}

and send message with:

try {
    String message = input.getText().toString() + "\n";
    outputStream.write(message.getBytes());
} catch (IOException e) {
    e.printStackTrace();
}

for file I/O use the same way.