如何在Node.js中按需调用中间件并发送响应

const express = require('express');
const app = express();

const middleware1 = (req, res, next) => {
  // 执行中间件1的任务
  next(); // 调用next()将控制权传递给下一个中间件函数
};

const middleware2 = (req, res, next) => {
  // 执行中间件2的任务
  next();
};

app.use(middleware1);
app.use('/path', middleware2);

app.get('/', (req, res) => {
  // 处理根路径的GET请求
  res.send('Hello, World!');
});

app.post('/path', (req, res) => {
  // 处理特定路径的POST请求
  res.json({ message: 'Success' });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});