gistfile1.java

try {
    final Socket socket = serverSocket.accept();
    final boolean[] accept = { false };
    new Handler(Looper.getMainLooper()).post(() -> {
                new AlertDialog.Builder(lobbyActivity)
                        .setTitle("Incoming Request")
                        .setMessage("Incoming Game Request")
                        .setPositiveButton(android.R.string.yes, (dialog, which) -> {
                                accept[0] = true;
                                try {
                                    socket.getOutputStream().write( 1);
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                                new Handler(Looper.getMainLooper()).post(() -> {
                                    Log.d("GAME", "Starting game from connection.");
                                    AndroidLauncher.network = new NetworkHandler(socket);
                                    Intent intent = new Intent(lobbyActivity, AndroidLauncher.class);
                                    lobbyActivity.startActivity(intent);
                                });
                            })
                        .setNegativeButton(android.R.string.no, (dialog, which) -> {
                                accept[0] = false;
                                try {
                                    socket.getOutputStream().write(0);
                                    socket.close();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            })
                        .setIcon(android.R.drawable.ic_dialog_alert)
                        .show();
            });
} catch (IOException e) {
    e.printStackTrace();
}