http-cache -> node.js 示例代码
1.index.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>http-cache</title> </head> <style> * { margin: 0; padding: 0; } body { display: flex; } </style> <body> <div style="width: 20%"> <h3>强制缓存</h3> <hr /> <h4>基于expires</h4> <img src="./img/test.webp" width="100" /> <hr /> <h4>基于cache-control</h4> <img src="./img/test1.webp" width="100" /> </div> <div style="width: 20%; margin-left: 30px"> <h3>协商缓存</h3> <hr /> <h4>基于last-modified</h4> <img src="./img/test2.webp" width="100" /> <hr /> <h4>基于etag</h4> <img src="./img/test3.webp" width="100" /> </div> </body> </html>
2.server.js
const http = require('http');
const fs = require('fs');
const url = require('url');
const etag = require('etag');
http.createServer((req, res) => {
console.log(req.method, `req.method`);
const { pathname } = url.parse(req.url);
switch (pathname) {
case '/':
const index = fs.readFileSync('./index.html');
res.statusCode = 200;
res.end(index);
break;
case '/img/test.webp':
const test = fs.readFileSync('./img/test.webp');
res.statusCode = 200;
res.setHeader('expires', new Date(Date.now() + 60 * 60 * 1000).toUTCString());
res.end(test);
break;
case '/img/test1.webp':
const test1 = fs.readFileSync('./img/test1.webp');
res.statusCode = 200;
res.setHeader('cache-control', 'max-age=20');
res.end(test1);
break;
case '/img/test2.webp':
const { mtime } = fs.statSync('./img/test2.webp');
const ifModifiedSince = req.headers['if-modified-since'];
if (ifModifiedSince === mtime.toUTCString()) {
console.log(`协商缓存`);
res.statusCode = 304;
res.end();
return;
}
const test2 = fs.readFileSync('./img/test2.webp');
res.statusCode = 200;
res.setHeader('cache-control', 'no-cache');
res.setHeader('last-modified', mtime.toUTCString());
res.end(test2);
break;
case '/img/test3.webp':
const test3 = fs.readFileSync('./img/test3.webp');
const etagContent = etag(test3);
const iNoneMatch = req.headers['if-none-match'];
if (iNoneMatch === etagContent) {
console.log(`协商缓存`);
res.statusCode = 304;
res.end();
return;
}
res.setHeader('cache-control', 'no-cache');
res.setHeader('etag', etagContent);
res.end(test3);
break;
default:
res.end();
break;
}
}).listen(5000, () => {
console.log(`server is running at http://localhost:5000`);
});
3.依赖列表
{ "name": "http-cache", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "keywords": [], "author": "", "license": "ISC", "devDependencies": { "@types/node": "^17.0.23", "etag": "^1.8.1" } }
