POST /api/users HTTP/1.1\r\n
Host: api.example.com\r\n
Content-Type: application/json\r\n
Content-Length: 48\r\n
Authorization: Bearer eyJhbG...\r\n
\r\n
{"name":"Alice","email":"alice@example.com"}

HTTP/1.1 201 Created\r\n
Content-Type: application/json\r\n
Location: /api/users/123\r\n
Content-Length: 62\r\n
\r\n
{"id":123,"name":"Alice","email":"alice@example.com"}

import socket

def raw_http_request():
    """手动构建 HTTP 请求，理解底层格式"""
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(("httpbin.org", 80))

    # 手动构建请求文本
    request = (
        "GET /get HTTP/1.1\r\n"
        "Host: httpbin.org\r\n"
        "User-Agent: raw-python/1.0\r\n"
        "Accept: application/json\r\n"
        "Connection: close\r\n"
        "\r\n"
    )

    sock.send(request.encode())
    
    # 接收响应
    response = b""
    while True:
        data = sock.recv(4096)
        if not data:
            break
        response += data

    sock.close()
    print(response.decode())

raw_http_request()

# GET — 获取资源
curl https://api.example.com/users/1

# POST — 创建资源
curl -X POST \
     -H "Content-Type: application/json" \
     -d '{"name":"Bob"}' \
     https://api.example.com/users

# PUT — 完整替换资源
curl -X PUT \
     -H "Content-Type: application/json" \
     -d '{"name":"Bob Updated","age":30}' \
     https://api.example.com/users/1

# PATCH — 部分更新
curl -X PATCH \
     -H "Content-Type: application/json" \
     -d '{"age":31}' \
     https://api.example.com/users/1

# DELETE — 删除资源
curl -X DELETE https://api.example.com/users/1

# HEAD — 仅获取响应头
curl -I https://api.example.com/users/1

# OPTIONS — 获取允许的方法
curl -X OPTIONS https://api.example.com/users -i

Host: www.example.com              # 必须，HTTP/1.1 要求
User-Agent: Mozilla/5.0 ...        # 客户端标识
Accept: text/html,application/json # 期望的响应格式
Accept-Language: zh-CN,en          # 语言偏好
Accept-Encoding: gzip, br          # 支持的压缩算法
Authorization: Bearer <token>      # 认证凭据
Content-Type: application/json     # 请求体格式
Content-Length: 128                # 请求体长度
If-None-Match: "etag-value"        # 缓存协商
Connection: keep-alive             # 连接管理

Content-Type: application/json; charset=utf-8
Content-Length: 256
Content-Encoding: gzip
Cache-Control: max-age=3600, public
ETag: "abc123"
Set-Cookie: session=xyz; HttpOnly; Secure
Location: /new-resource            # 用于重定向
Server: nginx/1.24
Access-Control-Allow-Origin: *     # CORS
Strict-Transport-Security: max-age=31536000  # HSTS

POST /api/v1/users HTTP/1.1
Host: api.myapp.com
Content-Type: application/json
Accept: application/json
X-Request-ID: 550e8400-e29b-41d4-a716-446655440000
Content-Length: 82

{
    "username": "alice",
    "email": "alice@example.com",
    "password": "P@ssw0rd123"
}

HTTP/1.1 201 Created
Content-Type: application/json
Location: /api/v1/users/123
X-Request-ID: 550e8400-e29b-41d4-a716-446655440000
Content-Length: 98

{
    "id": 123,
    "username": "alice",
    "email": "alice@example.com",
    "created_at": "2026-05-10T08:00:00Z"
}

HTTP/1.1 400 Bad Request
Content-Type: application/json
X-Request-ID: 550e8400-e29b-41d4-a716-446655440000
Content-Length: 112

{
    "error": {
        "code": "VALIDATION_ERROR",
        "message": "邮箱格式不正确",
        "details": [
            {"field": "email", "message": "必须是有效的邮箱地址"}
        ]
    }
}

const http = require('http');

const server = http.createServer((req, res) => {
    if (req.method === 'POST' && req.url === '/api/v1/users') {
        let body = '';

        req.on('data', chunk => body += chunk);
        req.on('end', () => {
            try {
                const data = JSON.parse(body);
                
                // 简单验证
                if (!data.email || !data.email.includes('@')) {
                    res.writeHead(400, {'Content-Type': 'application/json'});
                    res.end(JSON.stringify({
                        error: {
                            code: 'VALIDATION_ERROR',
                            message: '邮箱格式不正确'
                        }
                    }));
                    return;
                }

                // 创建用户
                res.writeHead(201, {
                    'Content-Type': 'application/json',
                    'Location': '/api/v1/users/123'
                });
                res.end(JSON.stringify({
                    id: 123,
                    username: data.username,
                    email: data.email,
                    created_at: new Date().toISOString()
                }));
            } catch (e) {
                res.writeHead(400, {'Content-Type': 'application/json'});
                res.end(JSON.stringify({error: {message: '请求体不是有效 JSON'}}));
            }
        });
    } else {
        res.writeHead(404, {'Content-Type': 'application/json'});
        res.end(JSON.stringify({error: {message: '路由不存在'}}));
    }
});

server.listen(3000, () => console.log('Server running on :3000'));

# JSON 格式
curl -X POST \
     -H "Content-Type: application/json" \
     -d '{"name":"Alice"}' \
     http://localhost:3000/api

# 表单格式
curl -X POST \
     -d "name=Alice&age=25" \
     http://localhost:3000/form

# 文件上传
curl -X POST \
     -F "file=@/path/to/image.jpg" \
     -F "description=my photo" \
     http://localhost:3000/upload