[FIXED] Should OutputStream be closed explicit in StreamingResponseBody?

Issue

I'm streaming a big external resource using StreamingResponseBody in a spring @RestController.

Question: should the OutputStream of the response body be closed explicit here?

@GetMapping("/{filename}")
public ResponseEntity<StreamingResponseBody> getFile(@PathVariable String filename) {
            StreamingResponseBody responseBody = outputStream -> {
                resolveExternally(outputStream, response, filename);

                //TODO should the stream be closed explicit here?
                //outputStream.close();
            };

            return ResponseEntity.ok(responseBody);
}

Solution

It will be closed by the container. Check StreamingResponseBodyReturnValueHandler.

OutputStream wraps a native HttpServletResponse.

HttpServletResponse response = webRequest.getNativeResponse(HttpServletResponse.class);
Assert.state(response != null, "No HttpServletResponse");
ServerHttpResponse outputMessage = new ServletServerHttpResponse(response);

If you follow it down you will get to CoyoteAdapter which is calling finishResponse() and closing OutputBuffer.

Answered By - Vahid
Answer Checked By - Gilberto Lyons (JavaFixing Admin)