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Node.js???????????

1. Node.js??

Node.js?????Chrome V8???????????JS????????????V8?????????API?????????????Web???????????Node.js??????????????I/O?????????????????????????????????

2. Node.js????

?????Node.js?????????

3. Node.js????

??????Node.js???

4. ??????

?? fs ?????????

const fs = require('fs');// ????fs.readFile('day.txt', 'utf-8', function(err, data) {    if (err) {        console.log('??????');    }    console.log(data);});// ????fs.writeFile('dayOut.txt', '?????', function(err) {    if (err) {        console.log('??????');    } else {        console.log('??????');    }});

5. ????

?? path ?????????

const path = require('path');// ????const finalPath = path.join('/a', '/b/c', '../', './d', 'e');console.log(finalPath);// ??????fs.readFile(path.join(__dirname, 'day.txt'), 'utf-8', function(err, data) {    console.log(data);});

6. HTTP????

Node.js??? http ???????????Web????

const http = require('http');const server = http.createServer();server.on('request', function(req, res) {    console.log('??????');    res.end('return data');});server.listen(80, function() {    console.log('??????localhost');});

7. Express????

Express ??????Node.js Web????????Web???API?

const express = require('express');const app = express();app.listen(80, function() {    console.log('??? http://localhost ???...');});

8. ??????

Express ??????????????

const express = require('express');const app = express();const router = express.Router();router.get('/user/list', function(req, res) {    res.send('?????? get /user/list');});app.use('/public', express.static('../day1'));app.listen(80, function() {    console.log('??? http://localhost ???...');});

9. ????????

9.1 MySQL??

??MySQL??????

const mysql = require('mysql');const conn = mysql.createConnection({    host: 'localhost',    port: 3306,    user: 'root',    password: 'password',    database: 'mydb'});conn.connect(function(err) {    if (err) {        console.log('????');    } else {        console.log('????');    }});

9.2 Session??

Session ???????????

const session = require('express-session');const app = express();app.use(session({    secret: 'your secret key',    resave: false,    saveUninitialized: true,    cookie: {}}));

9.3 JWT??

JWT ???????????

const jwt = require('jsonwebtoken');const token = jwt.sign({ id: 123 }, 'your secret', {    expiresIn: '1h'});// ?? tokenconst decodedToken = jwt.decode(token, 'your secret');

10. ???????

10.1 ????

Node.js ?????????????????????

• ?????fs?path?http
• ???????????JS??
• ???????? npm ??

10.2 ???

?? npm ????

// ???npm install express// ???npm uninstall express// ????npm install express -g

10.3 ???

? npm ????????

10.4 ??????

Node.js ???????

11. ??????

11.1 ????

?? npm ???? registry.npmmirror.com?

npm config set registry https://registry.npmmirror.comnpm install --save-dev nrmnrm use taobao

11.2 Express??????

?? express.static ???????

const express = require('express');const app = express();app.use(express.static('../public'));app.listen(80, function() {    console.log('????????');});

11.3 CORS ????

????? CORS ????

const cors = require('cors');const app = express();app.use(cors());app.listen(80, function() {    console.log('???????');});

12. ????

12.1 Express API??

???? API?

const express = require('express');const app = express();app.get('/api/test', function(req, res) {    res.send('API????');});app.listen(80, function() {    console.log('API??? http://localhost ???...');});

12.2 ?????

?? Express ? MySQL ???????

const express = require('express');const mysql = require('mysql');const app = express();const conn = mysql.createConnection({    host: 'localhost',    port: 3306,    user: 'root',    password: 'password',    database: 'mydb'});app.use('/api/test', function(req, res) {    const query = 'SELECT id FROM users';    conn.query(query, function(err, results) {        if (err) {            res.send('???????');        } else {            res.send(results);        }    });});app.listen(80, function() {    console.log('???????? http://localhost ???...');});

12.3 JWT????

?? JWT ? Express ???

const express = require('express');const jwt = require('jsonwebtoken');const app = express();app.use(express.json());// ?? tokenfunction verifyToken(req, res, next) {    const token = req.headers['x-access-token'];    jwt.verify(token, 'your secret', function(err, user) {        if (err) {            res.status(403).json({ error: '???token' });        } else {            next();        }    });}app.use('/api/auth', verifyToken);app.listen(80, function() {    console.log('JWT????? http://localhost ???...');});

13. ????

13.1 Express ???

?? nodemon ??????

npm install -g nodemonnodemon Main.js

13.2 ????

???????

const express = require('express');const router = express.Router();router.get('/user/list', function(req, res) {    res.send('????');});module.exports = router;

13.3 ?????

???????

const express = require('express');const app = express();app.use((req, res, next) => {    console.log('????????');    next();});app.get('/', function(req, res) {    res.send('?????????');});app.listen(80, function() {    console.log('?????? http://localhost ???...');});

?????????????Node.js????????????????Web???API?????

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