Node.js Express 响应事件

Node.js是一个基于Chrome V8 JavaScript引擎构建的开源、跨平台的JavaScript运行环境。它的出现极大地促进了JavaScript在服务器端的应用发展，并且成为了目前最流行的后端开发语言之一。Node.js的一个重要特点是非阻塞I/O模型，这意味着它能够处理大量并发请求而不会阻塞线程，从而提高了系统的吞吐量和性能。

javascript
const express = require('express');
const app = express();
app.get('/', (req, res) => {
  res.send('Hello, World!');
});
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

javascript
const express = require('express');
const app = express();
app.use((req, res, next) => {
  console.log('Request received');
  next();
});
app.get('/', (req, res) => {
  res.send('Hello, World!');
});
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

javascript
const express = require('express');
const app = express();
app.get('/', (req, res) => {
  throw new Error('Something went wrong');
});
app.use((err, req, res, next) => {
  console.error(err);
  res.status(500).send('Internal Server Error');
});
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});