问使用Android SDK进行Spotify长期登录

EN

private String getAccessTokenFromJsonStr(String spotifyJsonStr) throws JSONException {
    final String OWM_ACCESS_TOKEN = "access_token";
    String accessToken;

    try {
        JSONObject spotifyJson = new JSONObject(spotifyJsonStr);
        accessToken = spotifyJson.getString(OWM_ACCESS_TOKEN);
    } catch (JSONException e) {
        Log.e(LOG_TAG, e.getMessage(), e);
        e.printStackTrace();
    }

    return accessToken;
}

private String getSpotifyAccessToken(){
    String response;
    String accessToken;
    try {
        String serviceURL = "https://accounts.spotify.com/api/token";
        URL myURL = new URL(serviceURL);

        HttpsURLConnection myURLConnection = (HttpsURLConnection) myURL.openConnection();

        String userCredentials = "YOUR_USER_CREDENTIALS:YOUR_USER_CREDENTIALS";
        int flags = Base64.NO_WRAP | Base64.URL_SAFE;
        byte[] encodedString = Base64.encode(userCredentials.getBytes(), flags);
        String basicAuth = "Basic " + new String(encodedString);
        myURLConnection.setRequestProperty("Authorization", basicAuth);

        myURLConnection.setRequestMethod("POST");
        myURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        myURLConnection.setUseCaches(false);
        myURLConnection.setDoInput(true);
        myURLConnection.setDoOutput(true);
        System.setProperty("http.agent", "");

        HashMap postDataParams = new HashMap<String, String>();
        postDataParams.put("grant_type", "client_credentials");
        OutputStream os = myURLConnection.getOutputStream();
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));
        writer.write(getPostDataString(postDataParams));

        writer.flush();
        writer.close();
        os.close();

        response = "";
        int responseCode=myURLConnection.getResponseCode();

        Log.d(LOG_TAG, "response code is " + responseCode);

        if (responseCode == HttpsURLConnection.HTTP_OK) {
            String line;
            BufferedReader br=new BufferedReader(new InputStreamReader(myURLConnection.getInputStream()));
            while ((line=br.readLine()) != null) {
                response+=line;
            }
        }
        else {
            response="";
            String errLine;
            String errResponse = "";
            BufferedReader br=new BufferedReader(new InputStreamReader(myURLConnection.getErrorStream()));
            while ((errLine=br.readLine()) != null) {
                errResponse += errLine;
            }
            Log.d(LOG_TAG, "error response is " + errResponse);

        }

        Log.d(LOG_TAG, "response is " + response);


    } catch (Exception e){
        e.printStackTrace();
    }

    String accessTokenJsonStr = response.toString();
    try {
        accessToken = getAccessTokenFromJsonStr(accessTokenJsonStr);
        return accessToken;
    } catch (Exception e) {
        e.printStackTrace();
    }

    return "";
}