Spring Boot集成Google Drive API v3实现一次认证自动刷新令牌咨询

完全可以基于Google Drive API v3实现一次授权后自动刷新access token，你的现有代码已经包含核心实现逻辑，仅需少量调整即可稳定运行。

核心原理 #

Google OAuth2授权流程中，只要申请授权时指定access_type=offline参数，首次授权成功后即可获取到长期有效的refresh_token，Google官方Java客户端库会自动处理access_token过期后的刷新逻辑，无需手动编写刷新代码。

现有代码优势 #

• 已经在GoogleAuthorizationCodeFlow构建逻辑中设置了.setAccessType("offline")，满足获取refresh_token的前提条件
• 配置了FileDataStoreFactory，会自动将授权获取到的access_token、refresh_token持久化存储到指定的tokens目录，服务重启无需重复授权

优化方案 #

你当前的代码每次调用上传接口都会重复初始化授权流程和Drive实例，效率极低，建议将Drive实例改为单例，服务启动时仅初始化一次，优化后代码如下：

@Service
public class GoogleDriveService {
    private static final String APPLICATION_NAME = "application name";
    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);
    private static final String CREDENTIALS_FILE_PATH = "/client_secret.json";
    
    // Drive实例做成单例全局复用
    private Drive driveService;

    // 服务启动时初始化一次Drive实例
    @PostConstruct
    public void initDriveService() throws GeneralSecurityException, IOException {
        final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
        Credential credential = getCredentials(HTTP_TRANSPORT);
        this.driveService = new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
                .setApplicationName(APPLICATION_NAME)
                .build();
    }

    private Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
        InputStream in = GoogleDriveService.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
        if (in == null) {
            throw new FileNotFoundException("资源未找到: " + 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")
                // 新增配置，确保首次授权时强制返回refresh_token
                .setApprovalPrompt("force")
                .build();

        LocalServerReceiver receiver = new LocalServerReceiver.Builder().setHost("127.0.0.1").setPort(8089).build();
        return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
    }

    public boolean uploadGoogleDriveFile(java.io.File originalFile){
        try {
            File file = new File();
            file.setName(originalFile.getName());
            FileContent content = new FileContent("text/plain", originalFile);
            File uploadedFile  = driveService.files().create(file, content).setFields("id").execute();
            System.out.println("文件ID: " + uploadedFile.getId());
            return true;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }
}

注意事项 #

• 首次启动服务时，控制台会输出授权链接，访问链接完成一次授权即可，授权成功后tokens目录会生成凭证文件，后续启动/调用接口无需重复授权
• 服务器部署时需保证tokens目录拥有读写权限，避免凭证文件无法正常读写
• 若调整过授权范围，需删除tokens目录下的旧凭证文件，重新走一次授权流程
• 若之前授权过未拿到refresh_token，删除旧凭证重新授权即可

内容的提问来源于stack exchange，提问作者Wani