Node.js Express — RESTful API 增删改查

目标

使用 Express 框架构建一个完整的用户管理 RESTful API，实现 CRUD 操作，数据存储在内存中。

完整代码

// app.js
const express = require('express');
const app = express();
const port = 3000;

// 中间件：解析 JSON 请求体
app.use(express.json());

// 内存数据存储
let users = [
  { id: 1, name: 'Alice', email: 'alice@example.com' },
  { id: 2, name: 'Bob', email: 'bob@example.com' },
];
let nextId = 3;

// GET /users — 获取所有用户
app.get('/users', (req, res) => {
  res.json({ total: users.length, data: users });
});

// GET /users/:id — 获取单个用户
app.get('/users/:id', (req, res) => {
  const user = users.find(u => u.id === parseInt(req.params.id));
  if (!user) return res.status(404).json({ error: 'User not found' });
  res.json(user);
});

// POST /users — 创建用户
app.post('/users', (req, res) => {
  const { name, email } = req.body;
  if (!name || !email) {
    return res.status(400).json({ error: 'name and email are required' });
  }
  const user = { id: nextId++, name, email };
  users.push(user);
  res.status(201).json(user);
});

// PUT /users/:id — 更新用户
app.put('/users/:id', (req, res) => {
  const user = users.find(u => u.id === parseInt(req.params.id));
  if (!user) return res.status(404).json({ error: 'User not found' });
  const { name, email } = req.body;
  if (name) user.name = name;
  if (email) user.email = email;
  res.json(user);
});

// DELETE /users/:id — 删除用户
app.delete('/users/:id', (req, res) => {
  const index = users.findIndex(u => u.id === parseInt(req.params.id));
  if (index === -1) return res.status(404).json({ error: 'User not found' });
  users.splice(index, 1);
  res.status(204).send();
});

app.listen(port, () => {
  console.log(`API server listening at http://localhost:${port}`);
});

运行步骤

# 1. 初始化项目
npm init -y
npm install express

# 2. 保存上述代码为 app.js

# 3. 启动
node app.js

测试

# 获取所有用户
curl http://localhost:3000/users

# 创建用户
curl -X POST http://localhost:3000/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Charlie","email":"charlie@example.com"}'

# 更新用户
curl -X PUT http://localhost:3000/users/1 \
  -H "Content-Type: application/json" \
  -d '{"name":"Alice Updated"}'

# 删除用户
curl -X DELETE http://localhost:3000/users/3

预期输出

$ node app.js
API server listening at http://localhost:3000

请求	响应
GET /users	{"total":2,"data":[{...},{...}]}
POST /users	{"id":3,"name":"Charlie","email":"charlie@example.com"}
PUT /users/1	{"id":1,"name":"Alice Updated","email":"alice@example.com"}
DELETE /users/3	204 No Content

要点说明

• express.json() 中间件解析请求体 JSON
• RESTful 命名规范：资源复数形式（/users），HTTP 方法表达操作
• 状态码：200 成功、201 创建成功、204 删除成功无内容、400 参数错误、404 不存在