feign调用文件上传服务，传参MultipartFile

Required request part 'file' is not present

将MultypartFile name 设为 接口参数。

        MultipartFile multipartFile = new MockMultipartFile("file", fileName,
                ContentType.MULTIPART.toString(), new FileInputStream(file));
        return this.fileUploadFeign.handleFileUpload(multipartFile);

定义feign接口：

    @PostMapping(value = "/v1/files", consumes = "multipart/*", headers = "content-type=multipart/form-data")
    String handleFileUpload(@RequestPart("file") MultipartFile file);