I've been trying to write a web application using Google Plus API and i need to set up OAuth access with java , I searched a lot and found google java starter and other examples and they were very confusing, I can't figure out what the code that I should write to get the token
I hope if there is someone who can tell me how to get the OAuth access with java in straight forward steps, I saw other questions on stackoverflow.com but they weren't very helpful for me
so any help would be very appreciated :)
The latest Google+ Java Quickstart is pretty straightforward, perhaps you found an older project when searching? Also, the documentation for getting started on Google+ with Java should help to get you going.
The following snippet shows you the relevant code for exchanging the authorization code for an access token when using the hybrid client/server flow:
GoogleTokenResponse tokenResponse =
new GoogleAuthorizationCodeTokenRequest(TRANSPORT, JSON_FACTORY,
CLIENT_ID, CLIENT_SECRET, code, "postmessage").execute();
// Create a credential representation of the token data.
GoogleCredential credential = new GoogleCredential.Builder()
.setJsonFactory(JSON_FACTORY)
.setTransport(TRANSPORT)
.setClientSecrets(CLIENT_ID, CLIENT_SECRET).build()
.setFromTokenResponse(tokenResponse);
I'm removing the lines performing the requisite checks discussed in this thread for simplicity.
// Store the token in the session for later use.
request.session().attribute("token", tokenResponse.toString());
It's worth noting here that you want to persist these credentials unless the user disconnects your app. The sample is using a session because in production environments, the session can be DB-backed and will be restored after the server restarts.
After you have the access / refresh token and expiration time, build the credentials for the OAuth v2 token and then the library will internally refresh the access token appropriately. The following code shows how this is done on the quickstart by retrieving the token data from the user's session and also includes an API call performed by the client, proving the server's Java client is working:
// Build credential from stored token data.
GoogleCredential credential = new GoogleCredential.Builder()
.setJsonFactory(JSON_FACTORY)
.setTransport(TRANSPORT)
.setClientSecrets(CLIENT_ID, CLIENT_SECRET).build()
.setFromTokenResponse(JSON_FACTORY.fromString(
tokenData, GoogleTokenResponse.class));
// Create a new authorized API client.
Plus service = new Plus.Builder(TRANSPORT, JSON_FACTORY, credential)
.setApplicationName(APPLICATION_NAME)
.build();
// Get a list of people that this user has shared with this app.
PeopleFeed people = service.people().list("me", "visible").execute();
If you wanted to do this differently, you could explicitly construct the tokenData object from the access token, refresh token, and so on, before constructing the Plus service object.
Related
I am trying to make use of Google Contacts API with OAuth 2 authentication. But some of the old sample codes are now not working for this API.I found a sample code which is makes request for Access Token and in response Google servers would give me the Access Token for ~1 hour limit and a Refresh Token with.
BUT this code has some issue
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
String APPLICATION_NAME = "PROJECT_NAME";
String SERVICE_ACCOUNT_EMAIL = "NUMERCALS-ALPHANUMERICALS#developer.gserviceaccount.com";
java.io.File p12File = new java.io.File("PROJECT_NAME-NUMERICALS.p12");
GoogleCredential credential =
new GoogleCredential.Builder()
.setTransport(httpTransport)
.setJsonFactory(jsonFactory)
.setServiceAccountId(SERVICE_ACCOUNT_EMAIL)
.setServiceAccountScopes(
Collections.singleton("https://www.google.com/m8/feeds"))
.setServiceAccountPrivateKeyFromP12File(p12File)
.setServiceAccountUser("user#example.com")
.build();
if (!credential.refreshToken()) {
throw new RuntimeException("Failed OAuth to refresh the token");
}
ContactsService service = new ContactsService(APPLICATION_NAME);
service.setOAuth2Credentials(credential);
Query gQuery = new Query(new java.net.URL("https://www.google.com/m8/feeds/groups/user#example.com/full"));
gQuery.setMaxResults(32767);
ContactGroupFeed groupFeed = service.query(gQuery, ContactGroupFeed.class);
for (ContactGroupEntry group : groupFeed.getEntries()) {
And I am getting some issues with it
com.google.api.client.auth.oauth2.TokenResponseException: 400 Bad Request
{
"error" : "invalid_grant"
}
at com.google.api.client.auth.oauth2.TokenResponseException.from(TokenResponseException.java:105)
at com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:287)
at com.google.api.client.auth.oauth2.TokenRequest.execute(TokenRequest.java:307)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.executeRefreshToken(GoogleCredential.java:269)
at com.google.api.client.auth.oauth2.Credential.refreshToken(Credential.java:489)
at javaCode.FinalCode.main(FinalCode.java:68)
I am new to use OAuth2 for Google APIs so guide me if I am mistaken somewhere or provide a working code snippet.It would be great help.Thanks in advance.
In you example you are trying to use Service account to impersonate the user.
While this is possible, it can only be achieved under Google for work or Google for education accounts.
It would not work for normal gmail accounts.
If this is the case for your use case, then remember that the domain administrator should grant access to your application and also should grant Domain wide delegation of authority.
But if you are just trying to make some tests with the API, then it would be better if you use normal OAuth.
Check this tutorial, I know is for Drive, but there you can see the basic steps to get a authorization token. After you get it, the call to the different Google Apis is very similar.
I would recommend to check the OAuth Playground. There you can check the complete OAuth process and you can play with the API.
So my main application is written in Ruby/Rails and that is where the preliminary oauth2 action is happening. Currently I store the email and refresh token from that initial interaction, and now want to use a Scala script to retrieve data from the api in the background using the users credentials. (the point of an API no..?)
After following many examples from the google java api client example page:https://github.com/google/google-api-java-client-samples, I have found that they want me to re-authenticate users via opening a new tab and physically log in. Because I've already authenticated them, is there a way for me to simply continually retrieve data without requiring them to log in again, as this script should be running in the background?
To refresh an access token using the java-api-client library:
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential
val credential = new GoogleCredential.Builder()
.setTransport(transport)
.setJsonFactory(jsonFactory)
.setClientSecrets(CLIENT_ID, CLIENT_SECRET)
.build()
credential.setRefreshToken(refreshToken) // get token from DB or wherever you have persisted it
credential.refreshToken()
credential.getAccessToken // returns new, refreshed access token
I was trying to use the service account of my app to access to all documents of all users in my domain following this instruction:
https://developers.google.com/drive/delegation
But it didn't work.
Could you please help me out on this??
I tried to follow URL -
http://iambusychangingtheworld.blogspot.co.uk/2013/12/google-drive-api-how-work-with-domain.html
and code -
GoogleCredential credential = new GoogleCredential.Builder()
.setTransport(TRANSPORT)
.setJsonFactory(jsonFactory)
.setServiceAccountId("SERVICE_ACCOUNT_EMAIL")
.setServiceAccountPrivateKeyFromP12File(
new java.io.File("SERVICE_ACCOUNT_PKCS12_FILE_PATH"))
.setServiceAccountScopes(scopes)
.setServiceAccountUser("abc#xyz.com").build();
its working fine But should give me details for all the user for this domain... instead it gives me only for one useraccount.. In the Service account doc it says it should be able to access all the users data under this domain.. am I missing something>?
FYI... Scopes are added , APIS are enabled for this account
Is there any way I can get it??
I have also seen below links but was not of -
Not able to access my google drive Files with service account
The service account with domain-wide delegation allows you to access each account's data one at a time.
If you want to access all the users' data in a domain, you will need to generate a different token for each user (passing the email in the setServiceAccountUser() method) and make the API call for each user.
EDIT: Originally this question asked how I could authenticate with the Google Analytics API using only my API key. As vlatko pointed out, this isn't possible. Now I'm just focused on getting OAuth2 to work. I will be trying vlatko's suggestions when I get a chance and will update the question. In the meantime, feel free to contribute answers with anything you think I'm missing.
ORIGINAL QUESTION:
I'm trying to make requests to the Google Analytics API. I'm walking through the Hello Analytics tutorial trying to replicate the steps. Whatever I try, I can't seem to authenticate succesfully.
The tutorial says the following:
Open the file you created named HelloAnalyticsApi.java and add the
following method:
private static Analytics initializeAnalytics() throws Exception {
// Authorization.
Credential credential = OAuth2Native.authorize(
HTTP_TRANSPORT, JSON_FACTORY, new LocalServerReceiver(),
Arrays.asList(AnalyticsScopes.ANALYTICS_READONLY));
// Set up and return Google Analytics API client.
return Analytics.builder(HTTP_TRANSPORT, JSON_FACTORY)
.setApplicationName("Google-Analytics-Hello-Analytics-API-Sample")
.setHttpRequestInitializer(credential)
.build();
}
When a user encounters this script, the application will attempt to
open the default browser and navigate the user to a URL hosted on
google.com. At this point, the user will be prompted to login and
grant the application access to their data. Once granted, the
application will attempt to read a code from the browser window, then
close the window.
The difference is that I'm trying to do this with a servlet application, and I want to use simple API access with an API key (rather than an OAuth 2.0 client ID). I know that OAuth 2.0 is recommended, but I only need to access data that I own and want to simplify the technical requirements. I based this decision on this page, which says:
An API key is a unique key that you generate using the Console. When
your application needs to call an API that's enabled in this project,
the application passes this key into all API requests as a key={API_key}
parameter. Use of this key does not require any user action or
consent, does not grant access to any account information, and is not
used for authorization.
If you are only calling APIs that do not require user data, such as
the Google Custom Search API, then API keys may be simpler to
implement. However, if your application already uses an OAuth 2.0
access token, then there is no need to generate an API key as well. In
fact, Google ignores passed API keys if an OAuth 2.0 access token is
already associated with the corresponding project.
I can't find many code examples of auth flow just using the API key - most everything I've found shows using the client ID with the downloaded .p12 file, for example the GoogleCredential javadoc. The one example application I could find was Google's Books Sample app. Anyway, here's what I tried (mimicking the first request in the tutorial, which gets a list of the accounts from the management API):
Analytics analytics =
new Analytics.Builder(httpTransport, jsonFactory, null)
.setApplicationName("Dev API Access")
.build();
Management.Accounts.List list =
analytics.management().accounts().list().setKey(apiKey);
Accounts accounts = list.execute();
Where "Dev API Access" is the "Name" field in my API console dashboard. The API key is a server key restricted to my IP address. This fails with the following response:
401 Unauthorized
{
"code": 401,
"errors": [
{
"domain": "global",
"location": "Authorization",
"locationType": "header",
"message": "Login Required",
"reason": "required"
}
],
"message": "Login Required"
}
I also tried this:
Analytics analytics =
new Analytics.Builder(httpTransport, jsonFactory, null)
.setApplicationName("Dev API Access")
.setGoogleClientRequestInitializer(new AnalyticsRequestInitializer(apiKey))
.build();
Management.Accounts.List list = analytics.management().accounts().list();
Accounts accounts = list.execute();
Which shows the same error. What am I doing wrong here? Is OAuth2 required for analytics calls? If so, why does just using the API key work in the Books Sample app?
Moving on, I went ahead and tried OAuth2 anyway - I created a client ID and downloaded the .p12 private key file. But I couldn't get that working either. Here's what I tried:
Credential credential =
new GoogleCredential.Builder()
.setTransport(httpTransport)
.setJsonFactory(jsonFactory)
.setServiceAccountId(serviceAccountId)
.setServiceAccountScopes(AnalyticsScopes.ANALYTICS_READONLY)
.setServiceAccountPrivateKeyFromP12File(new File(p12FilePath))
.setServiceAccountUser(serviceAccountUser)
.build();
Analytics analytics =
new Analytics.Builder(httpTransport, jsonFactory, credential)
.setApplicationName("Dev API Access")
.build();
Management.Accounts.List list = analytics.management().accounts().list();
Accounts accounts = list.execute();
Where serviceAccountId is the email address of the Google account owning the project and serviceAccountUser is the email address listed on the generated client ID. This fails with the following:
400 Bad Request
{
"error": "invalid_grant"
}
What does "invalid grant" mean, and how do I successfully authenticate (ideally without OAuth2)?
To answer your first question: in general, OAuth2.0 is used for authorized access to user's private data, so getting user consent and obtaining an access token is required. In the case with Google Books API, however, if you're accessing public data, there is no need for end user consent so an API key is sufficient. If you try accessing non public data with the Books API, you'll still need an OAuth2 token.
The good news for your case is that even with OAuth2, you can bypass user involvement and streamline your flow with Service Accounts - assuming your application has access to the API. There is a way to set that up for the Analytics API, explained here (check the steps in the Service Accounts section). I think you are on the right track with your Credential builder, but I don't think you need to set the service account user in there, since you are not doing any user impersonation.
vlatko's answer got me on the right track. The issue turned out to be that I was confusing the owner email address with the service account email address. For example, I was doing the following:
Credential credential =
new GoogleCredential.Builder()
.setTransport(httpTransport)
.setJsonFactory(jsonFactory)
.setServiceAccountId("owneremail#gmail.com") //wrong
.setServiceAccountScopes(AnalyticsScopes.ANALYTICS_READONLY)
.setServiceAccountPrivateKeyFromP12File(new File(p12FilePath))
.setServiceAccountUser("xxx#developer.gserviceaccount.com") //unnecessary
.build();
When I needed to do this:
Credential credential =
new GoogleCredential.Builder()
.setTransport(httpTransport)
.setJsonFactory(jsonFactory)
.setServiceAccountId("xxx#developer.gserviceaccount.com")
.setServiceAccountScopes(AnalyticsScopes.ANALYTICS_READONLY)
.setServiceAccountPrivateKeyFromP12File(new File(p12FilePath))
.build();
Also, I had added owneremail#gmail.com as a user on my Analytics application - this similarly needed to be the service account email instead.
How can I authenticate programmatically to Google?
Now that ClientLogin (https://developers.google.com/accounts/docs/AuthForInstalledApps)
is deprecated, how can we perform a programmatic authentication to Google with OAuth2?
With ClientLogin we could perform a post to
https://www.google.com/accounts/ClientLogin
with email and password parameters and obtain the authentication token.
With OAuth2 i can't find a solution!
#
My app is a java background process.
I saw, following this link: developers.google.com/accounts/docs/OAuth2InstalledApp#refresh, how to obtain a new access token using a refreshed token.
The problem is that I can't find a java example about how to instantiate an Analytics object (for example) to perform a query when I have a new valid access token
This is my code that returns a 401 Invalid credentials when invoke the "execute()":
public class Test {
static final String client_id = "MY_CLIENT_ID";
static final String client_secret = "MY_SECRET";
static final String appName = "MY_APP";
private static final HttpTransport HTTP_TRANSPORT = new NetHttpTransport();
private static final JsonFactory JSON_FACTORY = new JacksonFactory();
static String access_token = "xxxx";
static String refreshToken = "yyyyy";
public static void main (String args[]){
try {
GoogleCredential credential =
new GoogleCredential.Builder()
.setTransport(HTTP_TRANSPORT)
.setJsonFactory(JSON_FACTORY)
.setClientSecrets(client_id, client_secret).build();
credential.setAccessToken(access_token);
credential.setRefreshToken(refreshToken);
//GoogleCredential
Analytics analytics = Analytics.builder(HTTP_TRANSPORT, JSON_FACTORY)
.setApplicationName(appName)
.setHttpRequestInitializer(credential)
.build();
Accounts accounts = analytics.management().accounts().list().execute();
} catch (Exception e) {
e.printStackTrace();
}
}
What is the problem?
Check the OAuth 2 flow for Installed Application:
https://developers.google.com/accounts/docs/OAuth2InstalledApp
It still requires the user to authenticate with a browser the first time, but then you can store the refresh token and use it for subsequent requests.
For alternative solutions, check the Device flow or Service Accounts, they are explained in the same documentation set.
I found the Google Java client to be overly complex and poorly documented. Here's plain and simple Servlet example with Google Oauth2. For a background process you'll need to request access_type=offline. As others have mentioned you need the user to do a one time authorization. After that you can request refresh tokens as google tokens expire in an hour.
Although I appreciate that the OP was originally targeting the OAuth2InstalledApp approach, I would like to point out a working solution using the OAuth2WebServer approach. They don't differ significantly and this worked for me. I have found the google OAuth library to be pretty good as it will handle most of the OAuth dance for you and it makes it easy to refresh the access token. The solution below depends on using a pre-obtained refresh token.
As the accepted answer states, to get OAuth authentication working (even for a Java background process) where the request relies upon access to user data
requires the user to authenticate with a browser the first time, but then you can store the refresh token and use it for subsequent requests.
From previous comments by the OP I see the following
So I followed OAuth2 for Web Server Applications (here offline access is documented) but I have still problems.
1) I perform the first request via browser and I obtain autenticaton code for offline access
2) I perform a java post of the authentication code and obtain acces token and refresh token
The approach I used is more like
1) I perform the first request via a browser and obtain the refresh token for offline access
2) In java I provide the refresh token to the library and the library will obtain the access token etc
specifically, using the google-api-java-client library the code is quite straightforward and note that I haven't set an access token as the OP did, as I am calling credential.refreshToken(); elsewhere. (I check if I have a valid access token already and if not call refresh prior to the API call)
private Credential generateCredentialWithUserApprovedToken() throws IOException,
GeneralSecurityException {
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
InputStreamReader inputStreamReader =
new InputStreamReader(jsonFileResourceForClient.getInputStream());
GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(jsonFactory, inputStreamReader);
return new GoogleCredential.Builder().setTransport(httpTransport).setJsonFactory(jsonFactory)
.setClientSecrets(clientSecrets).build().setRefreshToken(REFRESH_TOKEN);
}
Note this covers step 2 of my approach, and the REFRESH_TOKEN mentioned in step 1 can be obtained as explained below.
First there is a prior set up of a web app creating an OAuth 2.0 client ID on the Google console for Credentials where you end up with a downloaded json file which will be read into the GoogleClientSecrets object.
i.e.
Make sure you add the Google playground callback uri into Authorized redirect URIs
Then you have your client id and the client secret ready for the playground and you can also download the json which you can pull into your Java code.
The REFRESH_TOKEN is obtained by sending a request to the google oauth playground with the following configuration. Note that prior to Step 1 and selecting your scope you should go to settings to check that you are providing you own credentials and add your client id and secret just below that
Note that the Access type is Offline, which corresponds to this.
There is also a nice explanation on grabbing the refresh token here https://www.youtube.com/watch?v=hfWe1gPCnzc
That is enough to get going and is a one time set up!
Regarding refresh tokens you should be aware of their lifecycle as discussed in the docs here
In the oauthplayground you will see this
but on point 4 of the docs here it says this
Hmmm.
Also for reference see How do I authorise an app (web or installed) without user intervention? (canonical ?)
For applications that authenticate on behalf of themselves (i.e., to another application, traditionally by signing into a role account using a shared password), the OAuth2 alternative to ClientLogin offered by Google is Service Accounts:
https://developers.google.com/accounts/docs/OAuth2ServiceAccount