加载资源失败：服务器响应状态为 500内部服务器错误当我尝试上传图像时发生此错误

编程问答 2022-04-24

问题描述

我是 MEAN 开发的新手。我有两个输入字段和一个带有照片上传按钮的字段。虽然我设法在屏幕上显示上传的照片，但在服务器上上传时出现问题。有人可以帮忙吗？

我也收到此错误：

Error: ENOENT: no such file or directory,open 'C:\Something\Something\Something\Practice\finalappbackend\backedn\images\title-i-entered-1623300156286.jpeg'

这是我的后端代码：

app.js

const multer = require("multer");

const MIME_TYPE_MAP = {
  "image/png": "png","image/jpeg": "jpeg","image/jpg": "jpg",};

const storage = multer.diskStorage({
  destination: (req,file,cb) => {
    const isValid = MIME_TYPE_MAP[file.mimetype];
    let error = new Error("Invalid mime type");
    if (isValid) {
      error = null;
    }
    cb(error,"backedn/images");
  },filename: (req,cb) => {
    const name = file.originalname.toLowerCase().split(" ").join("-");
    const ext = MIME_TYPE_MAP[file.mimetype];
    cb(null,name + "-" + Date.Now() + "." + ext);
  },});


app.post(
  "/api/posts",multer({ storage: storage }).single("image"),(req,res,next) => {
    const post = new Post({
      title: req.body.title,content: req.body.content,});
    console.log(post);
    post.save().then((result) => {
      res.status(201).json({
        message: "Post added successfully",postId: result._id,});
    });
  }
);

这是我在前端的代码：

posts.service.ts

addPost(id: string,title: string,content: string,image: File) {
    const postData = new FormData();
    postData.append("title",title);
    postData.append("content",content);
    postData.append("image",image,title);
    this.http
      .post<{ message: string; postId: string }>(
        'http://localhost:3000/api/posts',postData
      )
      .subscribe((responseData) => {
        const post: Post = {id: responseData.postId,title: title,content: content}
        this.posts.push(post);
        this.postsUpdated.next([...this.posts]);
      });
  }

post-create.component.ts

imagePreview: string | ArrayBuffer;

onImagePicked(event: Event) {
    const file = (event.target as HTMLInputElement).files[0];
    this.form.patchValue({ image: file });
    this.form.get('image').updateValueAndValidity();
    const reader = new FileReader();
    reader.onload = () => {
      this.imagePreview = reader.result;
    };
    reader.readAsDataURL(file);
  }


onSavePost() {
    if (this.form.invalid) {
      return;
    }
    if (this.mode === 'create') {
      this.postsService.addPost(
        this.form.value.id,this.form.value.title,this.form.value.content,this.form.value.image
      );
    } else {
      this.postsService.updatePost(
        this.postId,this.form.value.content
      );
    }

    this.form.reset();
  }

和 post-create.component.html


<div>
      <button mat-stroked-button type="button" (click)="filePicker.click()">
        Pick Image
      </button>
      <input type="file" #filePicker (change)="onImagePicked($event)" />
</div>

解决方法

解释

ENOENT 代表：错误无输入。如果您查看错误：

Error: ENOENT: no such file or directory,open 'C:\Something\Something\Something\Practice\finalappbackend\backedn\images\title-i-entered-1623300156286.jpeg'

意思是：我无法打开'...finalappbackend\backedn\images'来保存图片，因为这个目录不存在。

在multer npm page

注意：您负责在提供时创建目录 目的地作为函数。传递字符串时，multer 将使 确保为您创建了该目录。

行动

确保目录已经创建。名称中可能有错别字 backedn。

angularangularbackendbackendfrontendimage-upload