極簡 Node.js 入門 - 5.3 靜態資源伺服器
阿新 • • 發佈:2020-10-19
> 極簡 Node.js 入門系列教程:[https://www.yuque.com/sunluyong/node](https://www.yuque.com/sunluyong/node)
>
> 本文更佳閱讀體驗:[https://www.yuque.com/sunluyong/node/static-server](https://www.yuque.com/sunluyong/node/static-server)
在[建立 HTTP 伺服器](https://www.yuque.com/sunluyong/node/http-server)實現了一個最簡單的靜態資源伺服器,可以對程式碼進行寫改造,增加資料夾預覽功能,暴露出一些配置,變成一個可定製的靜態資源伺服器模組
## 模組化
可定製的靜態資源伺服器理想的使用方式應該是這樣的
```javascript
const StaticServer = require('YOUR_STATIC_SERVER_FILE_PATH');
const staticServer = new StaticServer({
port: 9527,
root: '/public',
});
staticServer.start();
staticServer.close();
```
這樣的使用方式就要求程式碼實現模組化,Node.js 實現一個模組非常簡單
```javascript
const http = require('http');
const fs = require('fs');
const path = require('path');
const mime = require('mime-types');
const defaultConf = require('./config');
class StaticServer {
constructor(options = {}) {
this.config = Object.assign(defaultConf, options);
}
start() {
const { port, root } = this.config;
this.server = http.createServer((req, res) => {
const { url, method } = req;
if (method !== 'GET') {
res.writeHead(404, {
'content-type': 'text/html',
});
res.end('請使用 GET 方法訪問檔案!');
return false;
}
const filePath = path.join(root, url);
fs.access(filePath, fs.constants.R_OK, err => {
if (err) {
res.writeHead(404, {
'content-type': 'text/html',
});
res.end('檔案不存在!');
} else {
res.writeHead(200, {
'content-type': mime.contentType(path.extname(url)),
});
fs.createReadStream(filePath).pipe(res);
}
});
}).listen(port, () => {
console.log(`Static server started at port ${port}`);
});
}
stop() {
this.server.close(() => {
console.log(`Static server closed.`);
});
}
}
module.exports = StaticServer;
```
完整程式碼:[https://github.com/Samaritan89/static-server/tree/v1](https://github.com/Samaritan89/static-server/tree/v1)
執行 `npm run test` 可以測試
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589626073233-23b3458d-b6ba-4f6c-bc71-b1960697eebe.png#align=left&display=inline&height=156&margin=%5Bobject%20Object%5D&name=image.png&originHeight=312&originWidth=844&size=88956&status=done&style=none&width=422)
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589626096022-474f21e7-7872-4025-bd7f-f34f4f56db2a.png#align=left&display=inline&height=439&margin=%5Bobject%20Object%5D&name=image.png&originHeight=878&originWidth=1014&size=250932&status=done&style=none&width=507) ## 支援資料夾預覽 當訪問的路徑是資料夾的時候程式會報錯 ``` Error: EISDIR: illegal operation on a directory, read Emitted 'error' event on ReadStream instance at: at internal/fs/streams.js:217:14 at FSReqCallback.wrapper [as oncomplete] (fs.js:524:5) { errno: -21, code: 'EISDIR', syscall: 'read' } ``` 因為 fs.createReadStream 嘗試讀取資料夾,需要相容下訪問路徑是資料夾的時候,返回一個目錄頁,也就是在 fs.access 之後判斷檔案型別 ```javascript fs.access(filePath, fs.constants.R_OK, err => {
if (err) {
res.writeHead(404, {
'content-type': 'text/html',
});
res.end('檔案不存在!');
} else {
const stats = fs.statSync(filePath);
const list = [];
if (stats.isDirectory()) {
// 如果是資料夾則遍歷資料夾,生成改資料夾內的檔案樹
// 遍歷檔案內容,生成 html
} else {
res.writeHead(200, {
'content-type': mime.contentType(path.extname(url)),
});
fs.createReadStream(filePath).pipe(res);
}
}
});
```
> 遍歷生成 html 部分需要用到 [資料夾操作](https://www.yuque.com/sunluyong/node/qp1pcz) 章節介紹的知識,為了方便生成 HTML,demo 使用了 [Handlebar](https://handlebarsjs.com/) 模板引擎,主要邏輯
```javascript
if (stats.isDirectory()) {
// 如果是資料夾則遍歷資料夾,生成改資料夾內的檔案樹
const dir = fs.opendirSync(filePath);
let dirent = dir.readSync();
while (dirent) {
list.push({
name: dirent.name,
path: path.join(url, dirent.name),
type: dirent.isDirectory() ? 'folder' : 'file',
});
dirent = dir.readSync();
}
dir.close();
res.writeHead(200, {
'content-type': 'text/html',
});
// 對檔案順序重排,資料夾在檔案前面,相同型別按字母排序,不區分大小寫
list.sort((x, y) => {
if (x.type > y.type) {
// 'folder' > 'file', 返回 -1,folder 在 file 之前
return -1;
} else if (x.type == y.type) {
return compare(x.name.toLowerCase(), y.name.toLowerCase());
} else {
return 1;
}
});
// 使用 handlebars 模板引擎,生成目錄頁面 html
const html = template({ list });
res.end(html);
}
```
通過 git 程式碼修改記錄可以清晰看到本次的變更:[https://github.com/Samaritan89/static-server/commit/5565788dc317f29372f6e67e6fd55ec92323d0ea](https://github.com/Samaritan89/static-server/commit/5565788dc317f29372f6e67e6fd55ec92323d0ea)
同樣在專案根目錄執行 `npm run test` ,使用瀏覽器訪問 `127.0.0.1:9527` 可以看到目錄檔案的展示
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589630023090-9a7e0477-3cd6-4749-8287-7cd1fb2222fd.png#align=left&display=inline&height=169&margin=%5Bobject%20Object%5D&name=image.png&originHeight=337&originWidth=337&size=69354&status=done&style=none&width=168.5)
完整程式碼:[https://github.com/Samaritan89/static-server/tree/v2](https://github.com/Samaritan89/static-server/t
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589626073233-23b3458d-b6ba-4f6c-bc71-b1960697eebe.png#align=left&display=inline&height=156&margin=%5Bobject%20Object%5D&name=image.png&originHeight=312&originWidth=844&size=88956&status=done&style=none&width=422)
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589626096022-474f21e7-7872-4025-bd7f-f34f4f56db2a.png#align=left&display=inline&height=439&margin=%5Bobject%20Object%5D&name=image.png&originHeight=878&originWidth=1014&size=250932&status=done&style=none&width=507) ## 支援資料夾預覽 當訪問的路徑是資料夾的時候程式會報錯 ``` Error: EISDIR: illegal operation on a directory, read Emitted 'error' event on ReadStream instance at: at internal/fs/streams.js:217:14 at FSReqCallback.wrapper [as oncomplete] (fs.js:524:5) { errno: -21, code: 'EISDIR', syscall: 'read' } ``` 因為 fs.createReadStream 嘗試讀取資料夾,需要相容下訪問路徑是資料夾的時候,返回一個目錄頁,也就是在 fs.access 之後判斷檔案型別 ```javascript fs.access(filePath, fs.constants.R_OK, err =>
同樣在專案根目錄執行 `npm run test` ,使用瀏覽器訪問 `127.0.0.1:9527` 可以看到目錄檔案的展示
![image.png](https://cdn.nlark.com/yuque/0/2020/png/87727/1589630023090-9a7e0477-3cd6-4749-8287-7cd1fb2222fd.png#align=left&display=inline&height=169&margin=%5Bobject%20Object%5D&name=image.png&originHeight=337&originWidth=337&size=69354&status=done&style=none&width=168.5)
完整程式碼:[https://github.com/Samaritan89/static-server/tree/v2](https://github.com/Samaritan89/static-server/t