之前就已经写过一篇 浅谈 js 异步，最近有人问我怎么写批量下载。
方案有很多，用 request 模块自己封装一个 Promise 实现批量下载，用封装好的 got 模块直接批量，用递归批量。递归就不写了。
request
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
| const request = require("request");
const fs = require("fs");
const path = require("path");
const requestPromise = (url,filenane) =>{
return new Promise((resolve)=>{
request
.get(url)
.on("error", function(err) {
console.error(err);
}).on("end", () => {
resolve();
})
.pipe(fs.createWriteStream(filenane));
});
}
async function loop(){
for (let index = 0; index < array.length; index++) {
const url = array[index];
const file = path.basename(url);
await requestPromise(url,file);
}
}
|
got
这个原本就支持 Promise
1
2
3
4
5
6
7
8
9
10
11
12
| const got = require('got');
const fs = require("fs");
const path = require("path");
async function loop(){
for (let index = 0; index < array.length; index++) {
const url = array[index];
const file = path.basename(url);
await got.stream(url).pipe(fs.createWriteStream(file));
}
}
loop();
|
