Develop Reference

Spotify Android - Make Authorized Web Requests

I'm working on an Android app that implements the Spotify API to allow the users to listen to music. I've configured the Player that Spotify has created for android devices, but it's incredibly limited in terms of its functionality, so I've had to go through Spotify's Web API to do more advanced features.
I've hit a bug when trying to get a list of the user's own playlists. I'm making a request using:
URL url = new URL("https://api.spotify.com/v1/me/playlists");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
But instead of this command going through like it does for the other web API requests I've made, it throws the error:
java.io.FileNotFoundException: https://api.spotify.com/v1/me/playlists
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:242)
at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:210)
at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:25)
at com.tmacstudios.spotifyvoice.WebWrapper$override.searchUserPlaylist(WebWrapper.java:257)
at com.tmacstudios.spotifyvoice.WebWrapper$override.access$dispatch(WebWrapper.java)
at com.tmacstudios.spotifyvoice.WebWrapper.searchUserPlaylist(WebWrapper.java:0)
at com.tmacstudios.spotifyvoice.MainActivity$6.run(MainActivity.java:382)
at java.lang.Thread.run(Thread.java:818)
I'm not entirely sure why I'm getting this error, but I think it may have to do with not having the necessary authorization to make this request. Can anyone please help me solve this problem?

After studying the documentation some more, I was able to figure out a way to solve my problem. I was in fact getting the error since I wasn't using the proper authorization.
You can get the authorization token in OnActivityResult using this code:
AuthenticationResponse response = AuthenticationClient.getResponse(resultCode, intent);
if (response.getType() == AuthenticationResponse.Type.TOKEN) {
authToken = response.getAccessToken();
Log.e("MainActivity","Auth Token: "+authToken.toString());
...
Then when making the URL request, just pass in the authorization token as a header.
URL url = new URL("https://api.spotify.com/v1/me/playlists");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestProperty("Authorization", "Bearer " + authToken);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
...
Also note that you must have the permissions you are using enabled as scopes when you are forming the authorization request initially.

How to go for refresh token automatically when access token expired and get 401 using HttpURLConnection in android?

I have post request like below, Cant we make it automatic like Retrofit 2.0 interceptor if access token expires get refresh token and service call continues? without interruption?
URL url = new URL(myurl + "?access_token=" + access_token);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(100000000 /* milliseconds */);
conn.setConnectTimeout(150000000 /* milliseconds */);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
conn.setRequestProperty("charset", "utf-8");
conn.setDoInput(true);
conn.connect();
Is there any method to do this automatically when we get 401 response code ?

As far as i know, No way is provided for this in any framework as this is purely requirement based. You will have to post SERIAL calls as stated below :
Post Main Call with Access Token; Iff successful than Stop Else go to Step2
Post Call for New Access Token with Refresh Token, If Successful Update access token and again Post Main call like step 1 with updated Access token.
Same way if your refresh token can expire, than handle that in same SERIAL Way.
Hope it helps a bit.

GCM Client Based Device Group Management

I'm having issues adding GCM registration ID's to a device group client side in my Android app. I've followed all the instructions from https://developers.google.com/cloud-messaging/android/client-device-group but keep getting a 401 HTTP response. I've found the following posts but no one has an answer...
get notification key error 401 gcm https://android.googleapis.com/gcm/googlenotification
Google Cloud Messaging, returning 401 Unauthorized
Google Cloud Messaging, 401 Unauthorized is returned when creating notification key from client
How to successfully "Generate a Notification Key on the Client" with GCM?
I'm successfully getting an auth token from GoogleSignInApi and the method provided in Google's instructions but both give back 401 responses. I've ensured that I'm using the client ID for a Web Application in my Google Developer Console and still no luck. Here is my code snippet...
URL url = new URL("https://android.googleapis.com/gcm/googlenotification");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoOutput(true);
// HTTP request header
con.setRequestProperty("project_id", getString(R.string.gcm_defaultSenderId));
con.setRequestProperty("Content-Type", "application/json");
con.setRequestProperty("Accept", "application/json");
con.setRequestMethod("POST");
con.connect();
String accountName = getAccount();
//Initialize the scope using the client ID you got from the Console.
final String scope = "audience:server:client_id:"
+ "MY_WEB_APP_CLIENT_ID";
String idToken = "";
try {
idToken = GoogleAuthUtil.getToken(this, sharedPref.getString("googleEmail", ""), scope);
} catch (Exception e) {
e.printStackTrace();
}
// HTTP request
JSONObject data = new JSONObject();
data.put("operation", "add");
data.put("notification_key_name", "my_group_name");
data.put("registration_ids", new JSONArray(Arrays.asList(registrationId)));
data.put("id_token", idToken);
OutputStream os = con.getOutputStream();
os.write(data.toString().getBytes("UTF-8"));
os.close();
int responseCode = con.getResponseCode();
I don't think it matters for this HTTP post request but I've also ensured the right project and client ID (android) are stored in my google-services.json. Has anyone had any success managing device groups client side? If so what's different in my code from yours?

I'm not sure that it is possible to do this without the server API key. The 401 error indicates that some sort of HTTP Authorization header should be included if that URL is used for device group setup.
My best suggestion is to keep the server API key well hidden using a client-side keystore mechanism (http://developer.android.com/training/articles/keystore.html).
For details on how do do the whole thing using the SERVER_API key, please see here: Google Cloud Messaging (GCM) with local device groups on Android gives HTTP Error code 401
Hope this helps. :-)

Android HttpResponseCache and "Authorization" request header

I'm trying to get HttpResponseCache to cache responses to requests that include an "Authorization" header. I'm including this header because the API I am calling uses basic authentication.
HttpUrlConnection connection = initialiseConnection();
String usernameAndPasswordString = Base64.encodeToString(String.format("%s:%s", username, password).getBytes(), Base64.NO_WRAP);
connection.setRequestProperty("Authorization", String.format("basic %s", usernameAndPasswordString));`
To test this, I'm making the request with WiFi turned on. I'm then turning off WiFi and data and making the request again. I then get a FileNotFoundException when trying to read the response body.
InputStream inputStream = new BufferedInputStream(connection.getInputStream());
If I do the same thing but without the "Authorization" header (to an app on a different server that doesn't use basic auth), my code is able to read the response from the cache.
I am aware that an HTTP cache is not meant to cache a response that was the result of a request including an "Authorization" header, but does that mean that I just can't cache any responses from this server without writing my own cache? Is there any known way around this or to override this behaviour in HttpUrlConnection / HttpResponseCache?
Thanks in advance!

I managed to get to the bottom of this by going through the source code of HttpResponseCache (via https://github.com/candrews/HttpResponseCache, a custom version of the class by candrews taken from the Android source :) ). Including "public", "must-revalidate" or "s-maxage" directives in the Cache-Control header of the response will allow caching by HttpResponseCache even if the Authorization header was included in the request.

Confuse of Push Notification in Android

I followed this Push Notification tutorial.
When I finish the tutorial, I found out that two classes did not use which were AuthenticationUtil and MessageUtil.
Moreover, Google Login, this link seem unworkable. Second, This is the token id for the Android device or the account only? i thought push notification is push message to token id of Android device.
On the others hand, i found out that the bundle.putExtra(key, value), all the keys did not use it. For example put "app" but in C2DMRegistrationReceiver() did not get the key.
In this sendRegistrationIdToServer(), it seem like never being call out.
I am being confused by this tutorial about push notification.
Who can guide me or give me workable tutorial or example about push notification?
I would like pro to point out what's my wrong.
This is my registration id
public static final String[] REGISTRATION_ID = {
"APA91bFV6MwoAH0UNop69PZ2liKpSBUHSHenIuPzh44_6GdGKzVCLvoH_NM31eMZMVLZi-SAIFwP4iZaE72dSWkIh3GaD0RQYpPm9zO0ARWmnoxFyyyreL_KpQ9Qd_p0broclT12RhA4Ymk0cBT00CmpsbSHIwyxig",
"APA91bEwmxgvs7zNbKC4p0n4DoTEM73DTihnQgBOP8Gxhf2sVW-fgltugDgS1Fh2S4KvN1wQHbMNJEIzieJ9F1nNPqs3NWeKGbB7IBYpKJq4xmN4Z7uzkjZQQUKGD8jW--AwfQY5McINBto9GAL_87_u5WkIq-kx3g",
"APA91bH63Zgxn1X_MZ56UzrlRpffvmiLAIsqxvBUTMUHP2O_MT_VU9Ork_edXKHlml-PZSkjKEqdk8EKv5HvxbPdK1Vva3WtmqsPZfhXzEbtNIrwrqIvvRf7hL835rDc4t2E8EKUBj1dX2ta0OxY5pY3Xlhkyb1sBg",
"APA91bGqT5Wo6eUaMdqT5r9TlGbKSX6GN2W6r-RjrRXz5T5v3j87flcQRyfSajmMNGXuPVe-fwZydRmvyYu63tWnYohDmpJyKkXOxs8Vx6P_FplFQ__ufR_hekwqGOspeUc6bfc8fhbMPGN3Ft9l-bfrghJwwk79jw"};
Messageutil
public static int sendMessage(String auth_token, String registrationId,
String message, String title) throws IOException {
StringBuilder postDataBuilder = new StringBuilder();
postDataBuilder.append(PARAM_REGISTRATION_ID).append("=")
.append(registrationId);
postDataBuilder.append("&").append(PARAM_COLLAPSE_KEY).append("=")
.append("0");
postDataBuilder.append("&").append("data.payload").append("=")
.append(URLEncoder.encode(message, UTF8));
postDataBuilder.append("&").append("data.title").append("=")
.append(URLEncoder.encode(title, UTF8));
byte[] postData = postDataBuilder.toString().getBytes(UTF8);
// Hit the dm URL.
URL url = new URL("https://android.clients.google.com/c2dm/send");
HttpsURLConnection
.setDefaultHostnameVerifier(new CustomizedHostnameVerifier());
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded;charset=UTF-8");
conn.setRequestProperty("Content-Length",
Integer.toString(postData.length));
conn.setRequestProperty("Authorization", "GoogleLogin auth="
+ auth_token);
OutputStream out = conn.getOutputStream();
out.write(postData);
out.close();
int responseCode = conn.getResponseCode();
return responseCode;
}
private static class CustomizedHostnameVerifier implements HostnameVerifier {
public boolean verify(String hostname, SSLSession session) {
return true;
}
}
Messagesender
public static void main(String[] args) throws IOException {
String token = AuthenticationUtil.getToken(SecureStorage.USER,
SecureStorage.PASSWORD);
for (int i = 0; i < ServerConfiguration.REGISTRATION_ID.length; i++) {
MessageUtil.sendMessage(token,
ServerConfiguration.REGISTRATION_ID[i], "12358",
"印尼羽賽：馬2單1雙止步入選賽");
System.out.println(ServerConfiguration.REGISTRATION_ID[i]
.toString());
}
System.out.println(token);
}

You should follow this tutorial for android c2dm implementation.
For server, you could use anything, some code sample available on internet. For server I used .NET library called "C2DM Sharp"
The process is very simple like...
First register your google email for c2dm on - https://developers.google.com/android/c2dm/signup
Run the android application on Android 2.2 or higher and send the registrationID which you can get in "C2DMReceiver" or get that ID by writting in LOG
Use the server code, for testing purpose paste your registrationID in Server code and you are ready to go.
The basic flow of C2DM is ...
Register Phone for C2DM -> Get registrationID -> Send registrationID to server -> Server usees google id to get auth token -> server use registrationID and auth token to send message.

Google Cloud Messaging for Android
Important: C2DM(Android Cloud to Device Messaging Framework) has been officially deprecated as of June 26, 2012. This means that C2DM has stopped accepting new users and quota requests. No new features will be added to C2DM. However, apps using C2DM will continue to work. Existing C2DM developers are encouraged to migrate to the new version of C2DM, called Google Cloud Messaging for Android (GCM). See the C2DM-to-GCM Migration document for more information. Developers must use GCM for new development.
Kindly check the following link:
http://developer.android.com/guide/google/gcm/index.html

Please see my question here:
C2DM server. Should we use OAuth now?
There is some info and link to google group with answer.
In short..
Seems like OAuth2 will work, but I didn't find any working sample to implement
Client Login works and this is place where my confusion was. You need to:
Set up google account. I picked something like mynamec2dm#gmail.com.
Register for C2DM using this email. This is important.
On server-side use email/password you setup to get auth token.
Use this token to send messages from server.
Everything else is just like in all tutorials around.