上传文件请求后端url，自己排查了好几遍，也百度了可还是找不到原因，报错如下
xhr.js?b50d:178 POST http://127.0.0.1:9000/file/admin/upload 404 (Not Found)
dispatchXhrRequest @ xhr.js?b50d:178
xhrAdapter @ xhr.js?b50d:12
dispatchRequest @ dispatchRequest.js?5270:52
Promise.then (async)
request @ Axios.js?0a06:61
Axios. @ Axios.js?0a06:86
wrap @ bind.js?1d2b:9
uploadImage @ teacher.vue?174d:226
change @ teacher.vue?6298:205
invokeWithErrorHandling @ vue.runtime.esm.js?2b0e:1854
invoker @ vue.runtime.esm.js?2b0e:2179
original._wrapper @ vue.runtime.esm.js?2b0e:6917
createError.js?2d83:16 Uncaught (in promise) Error: Request failed with status code 404
at createError (createError.js?2d83:16)
at settle (settle.js?467f:17)
at XMLHttpRequest.handleLoad (xhr.js?b50d:61)
代码定位：
uploadImage(){
let _this = this;
let formData = new window.FormData();

            formData.append('file', document.querySelector('#file-upload-input').files[0]);
            _this.$ajax.post(process.env.VUE_APP_SERVER + '/file/admin/upload',
                formData, {
                    headers : {
                        'Content-Type': 'multipart/form-data'
                    },
                }

            ).then((response)=>{
                // console.log("保存结果：", response);
                let resp = response.data;
                let image = resp.content;
                console("头像地址：", image);
                _this.teacher.image = image;
            });
            // let instance = _this.$ajax.create({ headers: {'content-type': 'application/x-www-form-urlencoded'} });
            // instance.post(process.env.VUE_APP_SERVER + '/file/admin/upload', formData)
            // .then((response)=>{
            //     let resp = response.data;
            // })
        }

那个请求头部分我试过好几种也试过不写可就是不行报同样的错误，缓存我也清理过，头疼，辛苦老师指点迷津