video-download

@RestController
public class FileController {
    @GetMapping("/download/{fileId}")
    public ResponseEntity<Resource> download(@PathVariable("fileId") String fileId) {
        HttpHeaders headers = new HttpHeaders();
        Resource resource = new ClassPathResource("video/1.mp4", getClass().getClassLoader());
        headers.setContentType(MediaTypeFactory.getMediaType(resource).orElse(MediaType.APPLICATION_OCTET_STREAM));
        return ResponseEntity
                .ok()
                .headers(headers)
                .body(resource);
    }
}