Ant design上传图片之后，返回的response格式有点奇怪

#1

用ant 的upload组件上传图片，代码如下：

<Upload
                        name="itembank-image"
                        action="http://localhost:8080/api/upload"
                        listType="picture-card"
                        fileList={fileList}
                        beforeUpload={this.beforeUpload}
                        headers={
                            {Authorization: 'Bearer ' + localStorage.jwtToken }
                        }
                        onPreview={this.handlePreview}
                        onChange={this.handleUploadChange}
                    >
                        {fileList.length > 1 ? null : uploadButton}
                    </Upload>

handleUploadChange = (info) => {
        let { file,fileList }  = info ;
        console.log(file);
        fileList = fileList.map((file) => {
            if (file.response) {
                // Component will show file.url as link
                file.url = file.response.url;
            }
            return file;
        });
        this.setState({fileList});
    }

服务端是golang代码：

func UploadImage(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
	r.ParseMultipartForm(32 << 20)
	file, handler, err := r.FormFile("item-image")
	if err != nil {
		return
	}
	defer file.Close()

	filename := renameFile(handler.Filename) //在server side重新命名防止重复
	fullfilename := "/upload/img/"+filename
	targetPath := "."
	f, err := os.OpenFile(targetPath+fullfilename, os.O_WRONLY|os.O_CREATE, 0666) 
	if err != nil {
		return
	}
	defer f.Close()
	io.Copy(f, file)

	response := &FileInfoResponse{UID: 1, Name: filename, Status: "done", Url: fullfilename,Response:"test"}
	b, err := json.Marshal(response)
	w.Write(b)
}

服务端看到图片上传成功，返回一个新的文件地址给客户端。然后在客户端，我看到的是这样的数据：

response是一个字符串啊，这样根本无法使用 file.response.url 这样的语法来读取数据啊，请问是我哪里搞错了吗？

#2

。。。。。。