[SpringBoot] 구글드라이브 파일리스트 취득

Google Drive API의 files().list() 메소드를 호출하여 파일 목록을 가져옵니다. 결과로 반환된 FileList 객체에서 파일 목록을 가져와서 각 파일의 이름과 ID를 출력합니다.

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.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.File;
import org.springframework.web.multipart.MultipartFile;

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 GoogleDriveFileUploadExample {
    private static final String APPLICATION_NAME = "Google Drive API Java Quickstart";
    private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();
    private static final String TOKENS_DIRECTORY_PATH = "tokens";

    private static final List<String> SCOPES = Collections.singletonList(DriveScopes.DRIVE_FILE);
    private static final String CREDENTIALS_FILE_PATH = "/credentials.json";

    public static void uploadFile(MultipartFile file) throws IOException, GeneralSecurityException {
        NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
        Drive service = new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
                .setApplicationName(APPLICATION_NAME)
                .build();

        getFileList(service);
    }

    public void getFileList(Drive driveService) throws IOException {
        FileList result = driveService.files().list().setFields("nextPageToken, files(id, name, createdTime)").execute();
        List<com.google.api.services.drive.model.File> files = result.getFiles();
        for (com.google.api.services.drive.model.File file : files) {
            System.out.println("File Name: " + file.getName() + " File Id: " + file.getId());
        }
    }
    
    private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
        InputStream in = GoogleDriveFileUploadExample.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
                .setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
                .setAccessType("offline")
                .build();
        LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
        return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
    }
}