[20210329] Google Drive API

[JuHyun419]

Google Drive API

• Google Drive의 파일 리스트 출력하기(파일명)

package org.google.api.study.test;

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.javanet.NetHttpTransport;
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.File;
import com.google.api.services.drive.model.FileList;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;

public class DriveQuickStart {

    private static final String APPLICATION_NAME = "Google Drive API Java Quickstart";

    private static final JacksonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

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

    private static final String CLIENT_SECRET_FILE_NAME = "client_secret.json";

    //
    // Global instance of the scopes required by this quickstart. If modifying these
    // scopes, delete your previously saved credentials/ folder.
    //
    private static final List<String> SCOPES = Collections.singletonList(DriveScopes.DRIVE);


    private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
        java.io.File clientSecretFilePath = new java.io.File(CREDENTIALS_FOLDER, CLIENT_SECRET_FILE_NAME);
        if (!clientSecretFilePath.exists()) {
            throw new FileNotFoundException("Please copy " + CLIENT_SECRET_FILE_NAME //
                    + " to folder: " + CREDENTIALS_FOLDER.getAbsolutePath());
        }

        // Load client secrets.
        InputStream in = new FileInputStream(clientSecretFilePath);

        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(new FileDataStoreFactory(CREDENTIALS_FOLDER))
                .setAccessType("offline").build();

        return new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    }

    public static void main(String... args) throws IOException, GeneralSecurityException {

        System.out.println("CREDENTIALS_FOLDER: " + CREDENTIALS_FOLDER.getAbsolutePath());

        // 1: Create CREDENTIALS_FOLDER
        if (!CREDENTIALS_FOLDER.exists()) {
            CREDENTIALS_FOLDER.mkdirs();

            System.out.println("Created Folder: " + CREDENTIALS_FOLDER.getAbsolutePath());
            System.out.println("Copy file " + CLIENT_SECRET_FILE_NAME + " into folder above.. and rerun this class!!");
            return;
        }

        // 2: Build a new authorized API client service.
        final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();

        // 3: Read client_secret.json file & create Credential object.
        Credential credential = getCredentials(HTTP_TRANSPORT);

        // 5: Create Google Drive Service.
        Drive service = new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential) //
                .setApplicationName(APPLICATION_NAME).build();

        // Print the names and IDs for up to 10 files.
        FileList result = service.files().list().setPageSize(20).setFields("nextPageToken, files(id, name)").execute();
        List<File> files = result.getFiles();
        if (files == null || files.isEmpty()) {
            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());
            }
        }
    }
}

References

https://developers.google.com/drive/api/v3/quickstart/java

https://o7planning.org/11917/create-credentials-for-google-drive-api

https://o7planning.org/11889/manipulating-files-and-folders-on-google-drive-using-java