Android: What is transport and jsonFactory in GoogleIdTokenVerifier.Builder?

Question

in the blow code, whats is transport and jsonFactory ? (I do not understand)

https://developers.google.com/identity/sign-in/android/backend-auth#using-a-google-api-client-library

import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken; import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload; import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;  ...  GoogleIdTokenVerifier verifier = new GoogleIdTokenVerifier.Builder(transport /**Here**/, jsonFactory /**Here**/) .setAudience(Arrays.asList(CLIENT_ID)) // If you retrieved the token on Android using the Play Services 8.3 API or newer, set // the issuer to "https://accounts.google.com". Otherwise, set the issuer to  // "accounts.google.com". If you need to verify tokens from multiple sources, build // a GoogleIdTokenVerifier for each issuer and try them both. .setIssuer("https://accounts.google.com") .build();  // (Receive idTokenString by HTTPS POST)  GoogleIdToken idToken = verifier.verify(idTokenString); if (idToken != null) {   Payload payload = idToken.getPayload();    // Print user identifier   String userId = payload.getSubject();   System.out.println("User ID: " + userId);    // Get profile information from payload   String email = payload.getEmail();   boolean emailVerified = Boolean.valueOf(payload.getEmailVerified());   String name = (String) payload.get("name");   String pictureUrl = (String) payload.get("picture");   String locale = (String) payload.get("locale");   String familyName = (String) payload.get("family_name");   String givenName = (String) payload.get("given_name");    // Use or store profile information   // ...  } else {   System.out.println("Invalid ID token."); } 

Answer 1

Since all the other answers are blah blah blah, here's a short answer:

import com.google.api.client.http.javanet.NetHttpTransport; import com.google.api.client.json.gson.GsonFactory;  GoogleIdTokenVerifier verifier =     new GoogleIdTokenVerifier.Builder(new NetHttpTransport(), new GsonFactory());