Using Oauth 2.0 login gmail in android


Below steps require to login gmail using Oauth2.0

1- Select an account from your device using below code

public static AccountManager accountManager;
accountManager = AccountManager.get(this);
Account[] accounts = accountManager.getAccountsByType("com.google");

2- Get a Token from selected account using below code

private void onAccountSelected(final Account account) {
    accountManager.getAuthToken(account, AUTH_TOKEN_TYPE, null, this, 

           new AccountManagerCallback<Bundle>() {
        public void run(AccountManagerFuture<Bundle> future) {
            try {
                String token = future.getResult().getString(AccountManager.KEY_AUTHTOKEN);
                useToken(account, token);
            } catch (OperationCanceledException e) {
                onAccessDenied();
            } catch (Exception e) {
                handleException(e);
            }
        }
    }, null);
}

3-  now authenticate the token using user account and token you will be able to login.

Note:   After sometime token get unauthorized so you need to invalidate your token.

4- for re login you have to invalidate your token using below code

accountManager.invalidateAuthToken("com.google", token);

5- After invalidate you have to get a new token using below code

String newToken = AccountManager.get(this).getAuthToken(new Account(account, "com.google"),
       AUTH_TOKEN_TYPE, true, null, null).getResult().getString(AccountManager.KEY_AUTHTOKEN);

Thats all you need to do. Any suggestion will be appreciated.