npm install formidable -D

const formidable = require('formidable');

 1 router.post('/uploadFile', (req, res, next) => {
 2   let form = new formidable.IncomingForm();
 3   form.encoding = 'utf-8';
 4   //上传到服务器指定文件夹
 5   form.uploadDir =`public/${constant.UPLOAD_FOLDER}`;
 6   form.keepExtensions = true;     //保留后缀
 7   form.maxFieldsSize = constant.IMAGE_SIZE;
 8   let data = new MsgBean('上传失败',1);
 9   form.parse(req, (err, fields, files) => {
10     if (err) {
11       data.setContent(err);
12       res.send(data);
13       return;
14     }
15     let file = files.file;
16     let fileType = new RegExp(file.type, 'g');
17
18     let isLegal = fileType.test(constant.IMAGE_TYPE);
19     if(!isLegal) {//判断上传图片格式是否合法
20         data.msg('非法的图片格式');
21         res.send(data);
22         return;
23     }
24     let fileSize = file.size;
25     if(fileSize > constant.IMAGE_SIZE) {//上传图片超出最大限度
26         data.msg('图片大小超出最大限制');
27         res.send(data);
28         return;
29     }
30     let index = file.name.lastIndexOf('.');
31     let oldPath = files.file.path;
32     let uploadDate = new Date().getTime();
33     let fileName = `${file.name.slice(0, index)}_${uploadDate}_origin.${file.name.slice(index+1)}`;
34     let newPath = `public/${constant.UPLOAD_FOLDER}/${fileName}`;
35     fs.rename(oldPath, newPath, err => {//图片更名
36         if(err) {
37             data.setContent('图片解析失败');
38             res.send(data);
39             return;
40         }
41         let baseUrl = req.headers.host;
42         let imgUrl = `http://${baseUrl}/${constant.UPLOAD_FOLDER}/${fileName}`;
43         let result =  {
44             imgUrl
45         };
46         data.setCode(0);
47         data.setContent(result);
48         data.setMsg('上传成功');
49         res.send(data);
50     });
51   })
52 });