这是一个浏览器默认的请求
GET / HTTP/1.1
Host: 192.168.1.45:8080
Connection: keep-alive
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
实际上一个最简单的响应只需要包含一个状态码和内容长度，和正文内容了。
HTTP/1.1 200 OK
Content-Length: 14
<html>M</html>
显示效果如图：
