koa2的文件上传

使用koa2搭建文件上传服务，后端代码

const os = require('os');
const path = require('path');
const koaBody = require('koa-body');
const Koa = require('koa');
const app = new Koa();

const fs = require("fs");

const main = async function(ctx) {
  //const tmpdir = os.tmpdir(); //返回系统临时文件
  	
  const tmpdir = path.join(__dirname, "static");	
  
  const filePaths = [];
  const files = ctx.request.body.files || {};
  const params = ctx.request.body.fields
	 console.log(params);
   for (let key in files) {
   	const file = files[key];
   	if(Object.prototype.toString.call(file) == '[object Array]'){
   		for(var j = 0; j < file.length; j++ ){
   			witeFile(file[j]);
   		}
   	}else{
   		witeFile(file);
   		
   }
  }
  function witeFile(file){
  	const filePath = path.join(tmpdir, file.name);
    const reader = fs.createReadStream(file.path);
    const writer = fs.createWriteStream(filePath);
    reader.pipe(writer);
    filePaths.push(filePath);
  }

  

  ctx.body = filePaths;
};

app.use(koaBody({ multipart: true }));
app.use(main);
app.listen(3000);

　　前端代码

		<form action="http://localhost:3000/" method="post" enctype="multipart/form-data">
			<input type="text"	 name="name" id="" value="姓名" />
			<input type="text"	 name="pwd" id="" value="123456" />
			<input type="file" name="file" id="file" value="" multiple="multiple" />
			<input type="submit" value="提交"/>
		</form>