两条腿的oauth2:如何在没有特定API库的情况下调用google drive rest API

Question

import com.google.api.client.auth.oauth2.ClientCredentialsTokenRequest;
import com.google.api.client.auth.oauth2.ClientParametersAuthentication;
import com.google.api.client.auth.oauth2.TokenResponse;
...
public void oauth2Test() {
   String clientId = "...";
   String clientSecret = "...";
   ClientCredentialsTokenRequest request = new ClientCredentialsTokenRequest(
         new NetHttpTransport(),
         new JacksonFactory(),
         new GenericUrl("https://accounts.google.com/o/oauth2/auth"));
   request.setClientAuthentication(new ClientParametersAuthentication(clientId, clientSecret));
   TokenResponse response;
   try {
      response = request.execute();      
   } catch (Exception ex) {
      ex.printStackTrace();
   }
}

InputStream is = getClass().getResourceAsStream("JSONCredFile");
GoogleCredential credential = GoogleCredential.fromStream(is).createScoped(scopes);
Drive service = new Drive.Builder(new NetHttpTransport(), new JacksonFactory(), credential)
        .setApplicationName("My app")
        .build();
FileList result = service.files().list().setPageSize(10)
        .setFields("nextPageToken, files(id, name)")
        .execute();

POST /token HTTP/1.1
Accept-Encoding: gzip
User-Agent: Google-HTTP-Java-Client/1.23.0 (gzip)
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Host: oauth2.googleapis.com
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive
Content-Length: 771

grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer&assertion=<lots of encoded stuff>

GET /drive/v3/files?fields=nextPageToken,%20files(id,%20name)&pageSize=10 HTTP/1.1
Accept-Encoding: gzip
Authorization: Bearer ya29.c.Eln_BSgrx0afa85mdMstW5jzEvM5dotWpctSXl-DE1jeO2mmu1h0FErr_EZO05YnC-B1yz30IBwOyFXoWr_wwKxlZk08R6eZldNU-EAfrQ1yNftymn_Qqc_pfg

有更好的主意吗？

Answer 1

Google不支持grant_type=client_credentials，这就是使用OAuth客户机ID和secret来执行2LO的方式。