GoogleDriveUploader

DriveConfig.java

@Data
public class DriveConfig {

  @NotNull
  private String credentials;

  @NotNull
  private String driveId;

  @NotNull
  private String folderId;
}

GoogleDriveUploader.java

public class GoogleDriveUploader {

  private final DriveConfig config;
  private final Drive drive;

  public GoogleDriveUploader(AppConfig appConfig) throws IOException, GeneralSecurityException {
    config = appConfig.getDrive();
    GoogleCredentials credentials = ServiceAccountCredentials
        .fromStream(new ByteArrayInputStream(config.getCredentials().getBytes()))
        .createScoped(DriveScopes.all());
    drive = new Drive.Builder(
        GoogleNetHttpTransport.newTrustedTransport(),
        new GsonFactory(),
        new HttpCredentialsAdapter(credentials))
        .setApplicationName("Google Drive Sandbox")
        .build();
  }

  public List<File> list() throws IOException {
    FileList result = drive.files().list()
        .setCorpora("drive")
        .setDriveId(config.getDriveId())
        .setQ("'%s' in parents".formatted(config.getFolderId()))
        .setSupportsTeamDrives(true)
        .setIncludeItemsFromAllDrives(true)
        .execute();
    return result.getFiles();
  }

  public void upload(String filename, String content, String charset) throws IOException {
    File fileMeta = new File();
    fileMeta.setName(filename);
    fileMeta.setParents(List.of(config.getFolderId()));
    File f = drive.files()
        .create(fileMeta,
            new InputStreamContent("text/plain", new ByteArrayInputStream(content.getBytes(charset))))
        .setSupportsTeamDrives(true)
        .execute();
    System.out.print(f.getId());
  }
}