Android Studio项目访问Assets资源失败，调用DriveAPI遇IOException

我尝试使用Drive API将应用连接至Google Drive，但在获取凭证路径的输入流时触发了IOException。

相关代码 #

获取凭证的方法：

public Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT)
            throws IOException {
        // Load client secrets.
        InputStream in = new FileInputStream(CREDENTIALS_FILE_PATH);//getApplicationContext().getAssets().open(CREDENTIALS_FILE_PATH);//MainActivity.class.getResourceAsStream(CREDENTIALS_FILE_PATH);
        if (in == null) {
            throw new FileNotFoundException("Resource not found: " + CREDENTIALS_FILE_PATH);

        }
        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(new java.io.File(TOKENS_DIRECTORY_PATH)))
                .setAccessType("offline")
                .build();
        LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
        Credential credential = new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
        //returns an authorized Credential object.
        return credential;
    }

凭证路径定义：

private static final String CREDENTIALS_FILE_PATH = "CapturaVideo/app/src/main/assets/credentials.json";  // "credentials.json";

项目文件结构 #

credentials.json 文件位于项目的 app/src/main/assets 目录下

已尝试的读取方式 #

我试过两种资源读取方式，但均出现相同错误：

//getApplicationContext().getAssets().open(CREDENTIALS_FILE_PATH);
//MainActivity.class.getResourceAsStream(CREDENTIALS_FILE_PATH);

内容的提问来源于stack exchange，提问作者MISAEL DAVID LINARES WARTHON