google oauth - Java - GMail API - Authorization code -

i trying code below. console prints out url (after pasting in address bar on browser) sends me google's user-consent page , asks permission access account. redirects me html page - far good.

now, i'm not sure if receive token or authorization code. obtain from? , have send http rest call web application go along gmail api request, or can via java?

public class people {   public void setup() throws ioexception {         httptransport httptransport = new nethttptransport();         jacksonfactory jsonfactory = new jacksonfactory();          string clientid = "client_id";         string clientsecret = "secret";          string redirecturl = "http://localhost:8080/testinggmailmail/webapps/login.html";         string scope = "https://www.googleapis.com/auth/contacts.readonly";           string authorizationurl = new googlebrowserclientrequesturl(clientid,redirecturl,arrays.aslist(scope)).build();           // point or redirect user authorizationurl.         system.out.println("go following link in browser:");         system.out.println(authorizationurl);         } } 

yes, @dalmto correct in pointing out client library 1 should handling this.

a better design store user credentials application in directory.

private static final java.io.file data_store_dir = new java.io.file(     system.getproperty("user.home"), ".store/mail_credentials"); 

now, make global instance filedatastorefactory.

private static filedatastorefactory data_store_factory; 

instantiate data_store_factory before getting credentials preferably in static block.

data_store_factory = new filedatastorefactory(data_store_dir); 

download , store client_secret.json google developer console. use following method credentials:

public static credential authorize() throws ioexception {     // load client secrets.     inputstream in             = gmailquickstart.class.getresourceasstream("/client_secrets.json");     googleclientsecrets clientsecrets             = googleclientsecrets.load(json_factory, new inputstreamreader(in));      // build flow , trigger user authorization request.     googleauthorizationcodeflow flow             = new googleauthorizationcodeflow.builder(                     http_transport, json_factory, clientsecrets, scopes)             .setdatastorefactory(data_store_factory)             .setaccesstype("offline")             .build();     credential credential = new authorizationcodeinstalledapp(             flow, new localserverreceiver()).authorize("user");     system.out.println(             "credentials saved " + data_store_dir.getabsolutepath());     return credential; } 

whenever above method called, looks storedcredential in path provided data_store_dir. if found, code executes is. if not, browser open ask login , authorize app. credentials generated such stored in data_store_dir location. long storedcredential present, app won't ask permission. general purpose design can used other google apis.