Spring Support for customization of 404 response when RouterFunctionWebHandler finds no routes

Context Next to the default WebServer a service starts another server to handle admin requests on a different port. The admin webserver is connected to the HttpHandler created by RouterFunctions.toHttpHandler.

When the admin server processes a request for a path not mapped to any RouterFunction then the admin server responds with a 404 NotFound status code and an empty response body.

Currently it is not possible to have a different response body.

Changing the RouterFunctionWebHandler to return a Mono.error(new ResponseStatusException(HttpStatus.NOT_FOUND)) instead of ServerResponse.notFound().build() allows clients to implement an exception handler that customizes the response body.

Default behavior does not change because WebFluxResponseStatusExceptionHandler is the default handler.

Comment From: poutsma

Merged in 2f557d9.

Thank you for submitting a PR, and we are sorry it took this long to resolve.