静态资源服务器(HTTP 服务器)可以将静态文件(如 js、css、图片）等通过 HTTP 协议展现给客户端。本文介绍如何基于 Node 实现一个简易的静态资源服务器（类似于 serve）。
const fs = require("node:fs");
const fsp = require("node:fs/promises");
const http = require("node:http");
const server = http.createServer(async (req, res) => {
const stat = await fsp.stat("./index.html");
res.setHeader("content-length", stat.size);
fs.createReadStream("./index.html").pipe(res);
});
server.listen(3000, () => {
console.log("Listening 3000...");
});在上述示例中，我们创建了一个 http server，并以 stream 的方式返回一个 index.html 文件。其中，分别引入引入了 Node 中的 fs、fsp、http 模块，各个模块的作用如下：
serve 的核心功能非常简单，它以命令行形式指定服务的文件根路径和服务端口，并创建一个 http 服务。
使用 npm 包 arg 读取命令行参数，www.npmjs.com/package/arg。
使用 npm 包 chalk 在控制台输出带有颜色的文字信息，方便调试预览。
// Native - Node built-in module
const fs = require("node:fs");
const fsp = require("node:fs/promises");
const http = require("node:http");
const path = require("node:path");
// Packages
const arg = require("arg");
const chalk = require("chalk");
var config = {
entry: "",
rewrites: [],
redirects: [],
etag: false,
cleanUrls: false,
trailingSlash: false,
symlink: false,
};
/**
* eg: --port <string> or --port=<string>
* node advance.js -p 3000 | node advance.js --port 3000
*/
const args = arg({
"--port": Number,
"--entry": String,
"--rewrite": Boolean,
"--redirect": Boolean,
"--etag": Boolean,
"--cleanUrls": Boolean,
"--trailingSlash": Boolean,
"--symlink": Boolean,
});
const resourceNotFound = (response, absolutePath) => {
response.statusCode = 404;
fs.createReadStream(path.join("./html", "404.html")).pipe(response);
};
const processDirectory = async (absolutePath) => {
const newAbsolutePath = path.join(absolutePath, "index.html");
try {
const newStat = await fsp.lstat(newAbsolutePath);
return [newStat, newAbsolutePath];
} catch (e) {
return [null, newAbsolutePath];
}
};
/**
* @param { http.IncomingMessage } req
* @param { http.ServerResponse } res
* @param { config } config
*/
const handler = async (request, response, config) => {
// 从 request 中获取 pathname
const pathname = new URL(request.url, `http://${request.headers.host}`)
.pathname;
// 获取绝对路径
let absolutePath = path.resolve(
config["--entry"] || "",
path.join(".", pathname)
);
let statusCode = 200;
let fileStat = null;
// 获取文件状态
try {
fileStat = await fsp.lstat(absolutePath);
} catch (e) {
// console.log(chalk.red(e));
}
if (fileStat?.isDirectory()) {
[fileStat, absolutePath] = await processDirectory(absolutePath);
}
if (fileStat === null) {
return resourceNotFound(response, absolutePath);
}
let headers = {
"Content-Length": fileStat.size,
};
response.writeHead(statusCode, headers);
fs.createReadStream(absolutePath).pipe(response);
};
const startEndpoint = (port, config) => {
const server = http.createServer((request, response) => {
// console.log("request: ", request);
handler(request, response, config);
});
server.on("error", (err) => {
const { code, port } = err;
if (code === "EADDRINUSE") {
console.log(chalk.red(`address already in use [:::${port}]`));
console.log(chalk.green(`Restart server on [:::${port + 1}]`));
startEndpoint(port + 1, entry);
return;
}
process.exit(1);
});
server.listen(port, () => {
console.log(chalk.green(`Open http://localhost:${port}`));
});
};
startEndpoint(args["--port"] || 3000, args);
