In the QuickStart.java example on Java Quickstart they use OAuth client ID to identify the application, and this pops up a windows asking for Google credentials to use the application. You have to download a client_secret.json to modify a Google Sheet.
My question is: Can you evade the popping up window asking for Google credentials using an API Key or something else? And, if it's possible, how do you change the Java code in order to do that?
An API key could only work when accessing the resources owned by the project that created the key.
For resources like spreadsheets, you're typically accessing resources owned by a user. It would be pretty awful if you got access to my private sheets simply by having an API key.
So no, I wouldn't expect there to be any way to avoid getting authorization to work with a user's documents. However, you should be able to use the Java OAuth library to retain the auth token so you can avoid needing to ask for it more than once. (Unless the user revokes access, of course.)
As DalmTo says, you can use service account credentials if you're trying to access resources owned by the project (or which the project can be granted access to). Note that if you're running on AppEngine, Google Kubernetes Engine or Google Compute Engine, the service account credentials for that environment should be available automatically.
The popup window you are seeing is the Oauth2 consent screen. In order to access private user data you need to have consent of the user in order to access their data.
There is another option its called a service account. If the sheet you are trying to access is one that you as the developer have control of then you can create service account credeitals take the service account email address and grant the service account access to the sheet.
The best example for service account access with java that i am aware of is the one for Google Analytics you will have to alter it for Google sheets i may be able to help with that if you have any issues. hello analytics service account.
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.analytics.Analytics;
import com.google.api.services.analytics.AnalyticsScopes;
import com.google.api.services.analytics.model.Accounts;
import com.google.api.services.analytics.model.GaData;
import com.google.api.services.analytics.model.Profiles;
import com.google.api.services.analytics.model.Webproperties;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.io.IOException;
/**
* A simple example of how to access the Google Analytics API using a service
* account.
*/
public class HelloAnalytics {
private static final String APPLICATION_NAME = "Hello Analytics";
private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
private static final String KEY_FILE_LOCATION = "<REPLACE_WITH_JSON_FILE>";
public static void main(String[] args) {
try {
Analytics analytics = initializeAnalytics();
String profile = getFirstProfileId(analytics);
System.out.println("First Profile Id: "+ profile);
printResults(getResults(analytics, profile));
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Initializes an Analytics service object.
*
* @return An authorized Analytics service object.
* @throws IOException
* @throws GeneralSecurityException
*/
private static AnalyticsReporting initializeAnalytic() throws GeneralSecurityException, IOException {
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
GoogleCredential credential = GoogleCredential
.fromStream(new FileInputStream(KEY_FILE_LOCATION))
.createScoped(AnalyticsScopes.all());
// Construct the Analytics service object.
return new Analytics.Builder(httpTransport, JSON_FACTORY, credential)
.setApplicationName(APPLICATION_NAME).build();
}
private static String getFirstProfileId(Analytics analytics) throws IOException {
// Get the first view (profile) ID for the authorized user.
String profileId = null;
// Query for the list of all accounts associated with the service account.
Accounts accounts = analytics.management().accounts().list().execute();
if (accounts.getItems().isEmpty()) {
System.err.println("No accounts found");
} else {
String firstAccountId = accounts.getItems().get(0).getId();
// Query for the list of properties associated with the first account.
Webproperties properties = analytics.management().webproperties()
.list(firstAccountId).execute();
if (properties.getItems().isEmpty()) {
System.err.println("No Webproperties found");
} else {
String firstWebpropertyId = properties.getItems().get(0).getId();
// Query for the list views (profiles) associated with the property.
Profiles profiles = analytics.management().profiles()
.list(firstAccountId, firstWebpropertyId).execute();
if (profiles.getItems().isEmpty()) {
System.err.println("No views (profiles) found");
} else {
// Return the first (view) profile associated with the property.
profileId = profiles.getItems().get(0).getId();
}
}
}
return profileId;
}
private static GaData getResults(Analytics analytics, String profileId) throws IOException {
// Query the Core Reporting API for the number of sessions
// in the past seven days.
return analytics.data().ga()
.get("ga:" + profileId, "7daysAgo", "today", "ga:sessions")
.execute();
}
private static void printResults(GaData results) {
// Parse the response from the Core Reporting API for
// the profile name and number of sessions.
if (results != null && !results.getRows().isEmpty()) {
System.out.println("View (Profile) Name: "
+ results.getProfileInfo().getProfileName());
System.out.println("Total Sessions: " + results.getRows().get(0).get(0));
} else {
System.out.println("No results found");
}
}
}