如何使用Java管理多个Google帐户中的日历

Question

I have successfully been able to read,insert or delete events to one or more google calendars belongs to a single google account after following the guidance in developers.google.com . Here now, I want to do the same for multiple accounts using that method.

Here's the situation with some more info. In this case, I created a project in the Google Developers Console and turned on the API. Then I created the OAuth 2.0 client ID to authenticate users via a consent screen.

Then I tried to connect the calendars using the downloaded client secret JSON. In this case I was given a URL to display the consent screen and get the user authentication like mentioned below.

All went well and I could successfully read,insert or delete events to one or more google calenders belongs to the google account (that was initially authenticated).

Now, I want to access some other google accounts and manage their Calenders as well. In this case, for other accounts also, I got the successful verification codes via the URL to display the consent screen as mentioned below.

http://localhost:12345/Callback?code=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Received verification code. You may now close this window...

But I have no Idea how to use it with the Java program to manage these Ca lenders belong to different google accounts. It continously manages the calenders of the first authenticated account.

How to do this? Basically how to manage calenders in multiple google accounts via java using the approach mentioned in above mentioned developers.google.com guidance.

Code :

private static void viewEvents() throws IOException {

        com.google.api.services.calendar.Calendar service = getCalendarService();

        DateTime now = new DateTime(System.currentTimeMillis());

        Events events = service.events().list("primary")
            .setMaxResults(10)
            .setTimeMin(now)
            .setOrderBy("startTime")
            .setSingleEvents(true)
            .execute();

        List<Event> items = events.getItems();

        if (items.size() == 0) {
            System.out.println("No upcoming events found.");
        } else {
            System.out.println("Upcoming events");

            for (Event event : items) {    
                DateTime start = event.getStart().getDateTime();
                if (start == null) {
                    start = event.getStart().getDate();
                }
                System.out.printf("%s (%s)\n", event.getSummary(), start);
            }     
        }
    }

    public static com.google.api.services.calendar.Calendar getCalendarService() throws IOException {

        Credential credential = authorize();

        return new com.google.api.services.calendar.Calendar.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
                .setApplicationName(APPLICATION_NAME)
                .build();
    }

    public static Credential authorize() throws IOException {

        InputStream in = CalendarQuickstart.class.getResourceAsStream("/client_secret_1.0.0.json");
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
                                                                                .setDataStoreFactory(DATA_STORE_FACTORY)
                                                                                .setAccessType("online")
                                                                                .build();

        Credential credential = null;
        try {credential = new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");} catch (Exception e) {}

        System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());

        return credential;
    }

Answer 1

I found an answer in another way by my self.

Credential credential = new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");

We can do this by using the String parameter of authorize() method. (eg : "user").

Let's say you want to manage calenders in two accounts namal@gmail.com and lakmini@gmail.com,

1. Execute the autherize() method it giving the parameter "namal". Then you will get the URL for consent screen.
2. Approve it using the namal@gmail.com account. It will store the credentials for namal@gmail.com against the key "namal".
3. Execute the authorize() method it giving the parameter "lakmini". Then you will get the URL for consent screen.
4. Logout from the namal@gmail.com or send the URL to a browser that has been logged as "lakmini@gmail.com".
5. Approve it using the lakmini@gmail.com account. It will store the credentials for lakmini@gmail.com against the key "lakmini".
6. Now when you are using the key "namal" you will connect to the Calendars for namal@gmail.com. And when you are using the key "lakmini" you will connect to the Calendars for lakmini@gmail.com.