FileController constructor Null safety

  1. String pathOfDirectoryToServe,
  2. {FutureOr<Response> onFileNotFound(
    1. FileController controller,
    2. Request req

Creates a controller that serves files from pathOfDirectoryToServe.

File controllers append the path of an HTTP request to pathOfDirectoryToServe and attempt to read the file at that location.

If the file exists, its contents are sent in the HTTP Response body. If the file does not exist, a 404 Not Found error is returned by default.

A route to this controller must contain the match-all segment (*). For example:

   .link(() => FileController("build/web"));

In the above, GET /site/index.html would return the file build/web/index.html.

If pathOfDirectoryToServe contains a leading slash, it is an absolute path. Otherwise, it is relative to the current working directory of the running application.

If no file is found, the default behavior is to return a 404 Not Found. (If the Request accepts 'text/html', a simple 404 page is returned.) You may override this behavior by providing onFileNotFound.

The content type of the response is determined by the file extension of the served file. There are many built-in extension-to-content-type mappings and you may add more with setContentTypeForExtension. Unknown file extension will result in application/octet-stream content-type responses.

The contents of a file will be compressed with 'gzip' if the request allows for it and the content-type of the file can be compressed according to CodecRegistry.

Note that the 'Last-Modified' header is always applied to a response served from this instance.


FileController(String pathOfDirectoryToServe,
    {FutureOr<Response> onFileNotFound(FileController controller, Request req)?})
    : _servingDirectory =,
      _onFileNotFound = onFileNotFound!;