Unable to get the subscription information from Google Play Android Developer API

I got it working! The steps I followed:

Prerequisite

Before start, we need to generate a refresh token. To do this first we have to create an APIs console project:

1. Go to the APIs Console and log in with your Android developer
   account (the same account used in Android Developer Console to upload the APK).
2. Select Create project.
3. Go to Services in the left-hand navigation panel.
4. Turn the Google Play Android Developer API on.
5. Accept the Terms of Service.
6. Go to API Access in the left-hand navigation panel.
7. Select Create an OAuth 2.0 client ID:
   • On the first page, you will need to fill in the product name, but a
     logo is not required.
   • On the second page, select web application and set the redirect URI
     and Javascript origins. We will use it later the redirect URI.
8. Select Create client ID. Keep in mind the Client ID and the Client secret, we will use them later.

So, now we can generate the refresh token:

1. Go to the following URI (note that the redirect URI must match the value entered in the client ID exactly, including any trailing backslashes):

https://accounts.google.com/o/oauth2/auth?scope=https://www.googleapis.com/auth/androidpublisher&response_type=code&access_type=offline&redirect_uri=REDIRECT_URI&client_id=CLIENT_ID

1. Select Allow access when prompted.
2. The browser will be redirected to your redirect URI with a code parameter, which will look similar to 4/eWdxD7b-YSQ5CNNb-c2iI83KQx19.wp6198ti5Zc7dJ3UXOl0T3aRLxQmbwI. Copy this value.

Create a main class with:

public static String getRefreshToken(String code)
{

    HttpClient client = new DefaultHttpClient();
    HttpPost post = new HttpPost("https://accounts.google.com/o/oauth2/token");
    try 
    {
        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(5);
        nameValuePairs.add(new BasicNameValuePair("grant_type",    "authorization_code"));
        nameValuePairs.add(new BasicNameValuePair("client_id",     GOOGLE_CLIENT_ID));
        nameValuePairs.add(new BasicNameValuePair("client_secret", GOOGLE_CLIENT_SECRET));
        nameValuePairs.add(new BasicNameValuePair("code", code));
        nameValuePairs.add(new BasicNameValuePair("redirect_uri", GOOGLE_REDIRECT_URI));
        post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        org.apache.http.HttpResponse response = client.execute(post);
        BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
        StringBuffer buffer = new StringBuffer();
        for (String line = reader.readLine(); line != null; line = reader.readLine())
        {
            buffer.append(line);
        }

        JSONObject json = new JSONObject(buffer.toString());
        String refreshToken = json.getString("refresh_token");                      
        return refreshToken;
    }
    catch (Exception e) { e.printStackTrace(); }

    return null;
}

GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET and GOOGLE_REDIRECT_URI are the previously values.

Finally, we have our refresh token! This value does not expire, so we can store in some site, like a property file.

Accessing to Google Play Android Developer API

1. Getting the access token. We will need our previosly refresh token:

   private static String getAccessToken(String refreshToken){
   
   HttpClient client = new DefaultHttpClient();
   HttpPost post = new HttpPost("https://accounts.google.com/o/oauth2/token");
   try 
   {
       List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(4);
       nameValuePairs.add(new BasicNameValuePair("grant_type",    "refresh_token"));
       nameValuePairs.add(new BasicNameValuePair("client_id",     GOOGLE_CLIENT_ID));
       nameValuePairs.add(new BasicNameValuePair("client_secret", GOOGLE_CLIENT_SECRET));
       nameValuePairs.add(new BasicNameValuePair("refresh_token", refreshToken));
       post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
   
       org.apache.http.HttpResponse response = client.execute(post);
       BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
       StringBuffer buffer = new StringBuffer();
       for (String line = reader.readLine(); line != null; line = reader.readLine())
       {
           buffer.append(line);
       }
   
       JSONObject json = new JSONObject(buffer.toString());
       String accessToken = json.getString("access_token");
   
       return accessToken;
   
   }
   catch (IOException e) { e.printStackTrace(); }
   
   return null;
   

   }

2. Now, we can access to the Android API. I’m interesting in the expiration time of a subscription, so:

   private static HttpTransport HTTP_TRANSPORT = new NetHttpTransport();
   private static JsonFactory JSON_FACTORY = new com.google.api.client.json.jackson2.JacksonFactory();
   
   private static Long getSubscriptionExpire(String accessToken, String refreshToken, String subscriptionId, String purchaseToken){
   
   try{
   
       TokenResponse tokenResponse = new TokenResponse();
       tokenResponse.setAccessToken(accessToken);
       tokenResponse.setRefreshToken(refreshToken);
       tokenResponse.setExpiresInSeconds(3600L);
       tokenResponse.setScope("https://www.googleapis.com/auth/androidpublisher");
       tokenResponse.setTokenType("Bearer");
   
       HttpRequestInitializer credential =  new GoogleCredential.Builder().setTransport(HTTP_TRANSPORT)
               .setJsonFactory(JSON_FACTORY)
               .setClientSecrets(GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET)
               .build()
               .setFromTokenResponse(tokenResponse);
   
       Androidpublisher publisher = new Androidpublisher.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential).
               setApplicationName(GOOGLE_PRODUCT_NAME).
               build();
   
       Androidpublisher.Purchases purchases = publisher.purchases();
       Get get = purchases.get(GOOGLE_PACKAGE_NAME, subscriptionId, purchaseToken);
       SubscriptionPurchase subscripcion = get.execute();
   
       return subscripcion.getValidUntilTimestampMsec();
   
   }
   catch (IOException e) { e.printStackTrace(); }
   return null;
   

   }

And that’s all!

Some steps are from https://developers.google.com/android-publisher/authorization.