Java Google Contacts API访问服务帐户身份验证

Question

我正在尝试访问Googles Contacts API，但由于获得授权而失败。从其他（网络）语言开始，我习惯于使用API​​Console和公共API密钥（授权）。

GoogleCredential credential = new GoogleCredential().setAccessToken("<<PublicAPIKey>>");
System.out.println(credential.refreshToken());          // false

这样，我不能够刷新令牌并不能确定如何使用公共密钥的accessToken
......相反，我尝试了一个服务帐户：

private static final String USER_ACCOUNT_EMAIL = "[e-mail]";
private static final String SERVICE_ACCOUNT_EMAIL = "[e-mail]";
private static final String SERVICE_ACCOUNT_PKCS12_FILE_PATH = "xy.p12";

public App() {
    Set<String> scopes = new HashSet<String>();
    scopes.add("https://www.google.com/m8/feeds");

    try {
        GoogleCredential credential = new GoogleCredential.Builder()
            .setTransport(new NetHttpTransport())
            .setJsonFactory(new JacksonFactory())
            .setServiceAccountId(SERVICE_ACCOUNT_EMAIL)
            .setServiceAccountScopes(scopes)
            .setServiceAccountUser(USER_ACCOUNT_EMAIL)
            .setServiceAccountPrivateKeyFromP12File(new java.io.File(SERVICE_ACCOUNT_PKCS12_FILE_PATH))
            .build();

        System.out.println(credential.refreshToken());
        //System.out.println(credential.getAccessToken());
    } catch (GeneralSecurityException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

这是我的例外：

com.google.api.client.auth.oauth2.TokenResponseException: 401 Unauthorized
        at com.google.api.client.auth.oauth2.TokenResponseException.from(TokenResponseException.java:105)
        at com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:287)
        at com.google.api.client.auth.oauth2.TokenRequest.execute(TokenRequest.java:307)
        at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.executeRefreshToken(GoogleCredential.java:384)
        at com.google.api.client.auth.oauth2.Credential.refreshToken(Credential.java:489)
        at App.<init>(App.java:50)
        at App.main(App.java:29)

谢谢提示！

Answer 1

不调用setServiceAccountUser()我的代码就可以很好地工作。但是您只会拥有一个模拟帐户（service_account_mail），而不是您的个人联系人。

“ 401未经授权”异常的另一个可能来源是遥不可及credential.refreshToken()。调用是将访问代码写入引用所必需的。

在完成的课程下面：

import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.gdata.client.contacts.ContactsService;

import java.io.File;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.Collections;

public class Connector {

  private static ContactsService contactService = null;
  private static HttpTransport httpTransport;

  private static final String APPLICATION_NAME = "Your-App/1.0";
  private static final String SERVICE_ACCOUNT_EMAIL = "[e-mail]";

  private Connector() {
    // explicit private no-args constructor
  }

  public static ContactsService getInstance() {
    if (contactService == null) {
      try {
        contactService = connect();

      } catch (GeneralSecurityException | IOException e) {
        e.printStackTrace();
      }
    }

    return contactService;
  }

  private static ContactsService connect() throws GeneralSecurityException, IOException {
    httpTransport = GoogleNetHttpTransport.newTrustedTransport();

    // @formatter:off
    GoogleCredential credential = new GoogleCredential.Builder()
                                            .setTransport(httpTransport)
                                            .setJsonFactory(JacksonFactory.getDefaultInstance())
                                            .setServiceAccountId(SERVICE_ACCOUNT_EMAIL)
                                            .setServiceAccountScopes(Collections.singleton("https://www.google.com/m8/feeds"))
                                            .setServiceAccountPrivateKeyFromP12File(new File("key.p12"))
                                            .build();
    // @formatter:on

    if (!credential.refreshToken()) {
      throw new RuntimeException("Failed OAuth to refresh the token");
    }

    ContactsService myService = new ContactsService(APPLICATION_NAME);
    myService.setOAuth2Credentials(credential);
    return myService;
  }

}