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Node.js
Published on Sun Sep 12 2021 12:00:01 GMT+0000

Node.js 服务端开发

使用express搭建基础服务器并处理请求

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//initialize
const Port = 3000;//设置端口号，一般是3000
const express = require('express');
const { fstat } = require('fs');
const app = express();
process.env.PORT = Port;
app.use(express.static('public'))//allow browser access resources

//err catch
process.on('uncaughtException',function(err){}) //监听未捕获的异常
process.on('unhandledRejection',function(err,promise){}) //监听Promise没有被捕获的失败函数

//传送文件的方法
app.get('/borrow', (req, res) => {
  res.setHeader('Content-Type','text/html');
  res.sendFile('public/borrow/borrow.html',{ root : __dirname});
  //由于sendFile要求使用绝对地址，所以要将根目录设置为当前文件夹
})

app.listen(Port, () => console.log('服务器已就绪，运行在端口'+Port))//输出服务器启动信息

基本的请求处理方式（以数据库为例）：

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//database
const mysql = require('mysql');
let databaseConnection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: '123456',
  database: 'books',
  port: 3306
});
databaseConnection.connect();

app.get('/userinfo/*', (req, res) => {
  let info = req.url;
  let infoS = info.split('/');
  let user = infoS[2];

  let returnUser;
  let userSelect = 'SELECT name from users where ID = ' + user;
  databaseConnection.query(userSelect, function (error, results, fields) {
    if (error) throw error;
    returnUser = results[0].name;
    res.send(returnUser);
  });

})

处理表单，返回token：

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app.post('/test_postForm', function (req, res) {
  let receivedForm = req.body;
  console.log('表单已获取');
  let token = receivedForm['user_name'];
  let resUrl = '/userMain?token='+token;
  res.redirect(resUrl);
});