Spring Boot REST API : Upload & Download files

@RestController
@RequestMapping("/api/files")
public class FileController {

    private static final String UPLOAD_DIR = "uploads/";

    // Handle file upload
    @PostMapping("/upload")
    public ResponseEntity<String> uploadFile(@RequestParam("file") MultipartFile file) {
        try {
            Path uploadPath = Paths.get(UPLOAD_DIR);
            if (!Files.exists(uploadPath)) Files.createDirectories(uploadPath);

            Path filePath = uploadPath.resolve(file.getOriginalFilename());
            Files.copy(file.getInputStream(), filePath, StandardCopyOption.REPLACE_EXISTING);
            return ResponseEntity.ok("File uploaded successfully: " + file.getOriginalFilename());

        } catch (IOException e) {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
                                 .body("Error uploading file: " + e.getMessage());
        }
    }

    // Handle file download
    @GetMapping("/download/{filename}")
    public ResponseEntity<Resource> downloadFile(@PathVariable String filename) {
        try {
            Path filePath = Paths.get(UPLOAD_DIR).resolve(filename).normalize();
            Resource resource = new UrlResource(filePath.toUri());

            if (resource.exists()) {
                return ResponseEntity.ok()
                        .contentType(MediaType.APPLICATION_OCTET_STREAM)
                        .header(HttpHeaders.CONTENT_DISPOSITION,
                                "attachment; filename=\"" + resource.getFilename() + "\"")
                        .body(resource);
            } else {
                return ResponseEntity.notFound().build();
            }

        } catch (MalformedURLException e) {
            return ResponseEntity.badRequest().build();
        }
    }
}