如何获取wifi上网ssid并上传到Firebase？

Question

我想在扫描结果中获取ssid并上传到firebase，但是没有任何内容放入数据库中。我在下面的代码中缺少什么？

private void uploadWifiList() {

    mWifiManager = (WifiManager) (WifiManager) getActivity().getApplicationContext().getSystemService(WIFI_SERVICE);
    mWifiManager.startScan();
    Toast.makeText(getContext(), "Scanning....", Toast.LENGTH_SHORT).show();

    FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();

    DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();

    ArrayList<String> wifis;
    wifis = new ArrayList<String>(); //initialize wifis

    List<ScanResult> scanResults = mWifiManager.getScanResults();
    wifis.clear();

    for (int i = 0; i < scanResults.size(); i++) {
        String rssid = scanResults.get(i).SSID;
        wifis.add(rssid);

        databaseReference.child("ssid").child(rssid).setValue(true);
    }

    ArrayList<String> userlist = new ArrayList<>();
    userlist.add(user.getDisplayName());

    DatabaseReference databaseReference1 = FirebaseDatabase.getInstance().getReference();
    for(String userlista : userlist) {
        databaseReference1.child("userlist").child(userlista).setValue(true);
    }
}