Google Drive访问

Question

我尝试运行这段Java代码，以便列出我的Google Drive中的所有文件：

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;

public class Quickstart
{
    /**
     * Application name.
     */
    private static final String APPLICATION_NAME = "Drive API Java Quickstart";

    /**
     * Directory to store user credentials for this application.
     */
    private static final java.io.File DATA_STORE_DIR = new java.io.File(
        System.getProperty("user.home"), ".credentials/drive-java-quickstart");

    /**
     * Global instance of the {@link FileDataStoreFactory}.
     */
    private static FileDataStoreFactory DATA_STORE_FACTORY;

    /**
     * Global instance of the JSON factory.
     */
    private static final JsonFactory JSON_FACTORY
        = JacksonFactory.getDefaultInstance();

    /**
     * Global instance of the HTTP transport.
     */
    private static HttpTransport HTTP_TRANSPORT;

    /**
     * Global instance of the scopes required by this quickstart.
     *
     * If modifying these scopes, delete your previously saved credentials at ~/.credentials/drive-java-quickstart
     */
    private static final List<String> SCOPES = Arrays.asList(DriveScopes.DRIVE_METADATA_READONLY);

    static
    {
        try
        {
            HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
            DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR);
        }
        catch (Throwable t)
        {
            t.printStackTrace();
            System.exit(1);
        }
    }

    /**
     * Creates an authorized Credential object.
     *
     * @return an authorized Credential object.
     * @throws IOException
     */
    public static Credential authorize() throws IOException
    {
        // Load client secrets.
        InputStream in
            = Quickstart.class.getResourceAsStream("/development-241a19899242.json");
        GoogleClientSecrets clientSecrets
            = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        // Build flow and 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 to " + DATA_STORE_DIR.getAbsolutePath());
        return credential;
    }

    /**
     * Build and return an authorized Drive client service.
     *
     * @return an authorized Drive client service
     * @throws IOException
     */
    public static Drive getDriveService() throws IOException
    {
        Credential credential = authorize();
        return new Drive.Builder(
            HTTP_TRANSPORT, JSON_FACTORY, credential)
            .setApplicationName(APPLICATION_NAME)
            .build();
    }

    public static void main(String[] args) throws IOException
    {
        // Build a new authorized API client service.
        Drive service = getDriveService();

        // Print the names and IDs for up to 10 files.
        FileList result = service.files().list()
            .setPageSize(10)
            .setFields("nextPageToken, files(id, name)")
            .execute();
        List<File> files = result.getFiles();
        if (files == null || files.size() == 0)
        {
            System.out.println("No files found.");
        }
        else
        {
            System.out.println("Files:");
            for (File file : files)
            {
                System.out.printf("%s (%s)\n", file.getName(), file.getId());
            }
        }
    }
}

当我运行代码时，我被重定向到登录页面，以输入我的Google电子邮件凭据。如何跳过这一步？代码我将完全在后台使用，我需要在JSON文件中使用凭据。

Answer 1

您可能希望使用服务帐户和Perform Google Apps Domain-Wide Delegation of Authority进行检查。

在企业应用程序中，您可能希望以编程方式访问用户数据，而无需他们进行任何手动授权。在Google Apps域中，域管理员可以向第三方应用程序授予对其用户数据的全域访问权限-这称为全域授权。要以这种方式委派授权，域管理员可以在OAuth 2.0中使用服务帐户。

这是creating a service account的链接

授权服务帐户代表域中的用户访问数据的

有时被称为“委派域范围的授权”给服务帐户。

如果您已经委派了对服务帐户的全域访问，并且希望模拟用户帐户，请使用GoogleCredential工厂的setServiceAccountUser方法指定该用户帐户的电子邮件地址。例如：

GoogleCredential credential = new GoogleCredential.Builder()
    .setTransport(httpTransport)
    .setJsonFactory(JSON_FACTORY)
    .setServiceAccountId(emailAddress)
    .setServiceAccountPrivateKeyFromP12File(new File("MyProject.p12"))
    .setServiceAccountScopes(Collections.singleton(SQLAdminScopes.SQLSERVICE_ADMIN))
    .setServiceAccountUser("user@example.com")
    .build();

还有一个关于Google Drive API with a Service Account的教程，它不是用Java语言编写的，但我希望这能帮助你理解如何使用Google Drive和服务帐户。

是否要上载到您个人有权控制的帐户？您不需要用户在Google上进行身份验证。您需要使用的是带有service account的Google Drive API。

希望这能有所帮助。