Code for Device B (Discoverer)

gistfile1.txt

 private void startDiscovery() {
        DiscoveryOptions discoveryOptions = new DiscoveryOptions.Builder().setStrategy(STRATEGY).build();
        Nearby.getConnectionsClient(BaseApplication.getInstance()
                .getActivity()).
                startDiscovery(SERVICE_ID, new EndpointDiscoveryCallback() {
                    @Override
                    public void onEndpointFound(@NonNull String endpointId, @NonNull DiscoveredEndpointInfo discoveredEndpointInfo) {
                        Nearby.getConnectionsClient(BaseApplication.getInstance()
                                .getActivity()).
                                requestConnection("Device B", endpointId, new ConnectionLifecycleCallback() {
                                    @Override
                                    public void onConnectionInitiated(@NonNull String endpointId, @NonNull ConnectionInfo connectionInfo) {
                                        Nearby.getConnectionsClient(BaseApplication.getInstance().getActivity()).acceptConnection(endpointId, mPayloadCallback);
                                    }
                                    @Override
                                    public void onConnectionResult(@NonNull String s, @NonNull ConnectionResolution connectionResolution) {
                                        switch (connectionResolution.getStatus().getStatusCode()) {
                                            case ConnectionsStatusCodes.STATUS_OK:
                                                // We're connected! Can now start sending and receiving data.
                                                break;
                                            case ConnectionsStatusCodes.STATUS_CONNECTION_REJECTED:
                                                // The connection was rejected by one or both sides.
                                                break;
                                            case ConnectionsStatusCodes.STATUS_ERROR:
                                                // The connection broke before it was able to be accepted.
                                                break;
                                            default:
                                                // Unknown status code
                                        }
                                    }
                                    @Override
                                    public void onDisconnected(@NonNull String s) {
                                    }
                                });
                    }
                    @Override
                    public void onEndpointLost(@NonNull String s) {
                        // disconnected 
                    }
                }, discoveryOptions);
    }