[Vuejs]-Request-Body(req.body) shows value but Request-QueryParams(req.queryParams) shows null value?

Thats because req.queryParams is used to get URL params. Example: http://localhost:1234/formData?name=Bruno&address=earth. Try to use this example from the official documentation of Spark Java. Here, it teaches you how to get a file from a multipart. It might work with some changes.