HTTP协议

http协议

HTTP协议是Hyper Text Transfer Protocol（超文本传输协议）

HTTP协议工作于客户端-服务端架构为上，浏览器作为HTTP客户端通过URL向HTTP服务端即WEB服务器发送所有请求。

WEB服务器根据接收到请求后，向客户端发送响应信息

http协议特性

（1）基于tcp/ip

（2）基于请求 - 响应模式

（3）无状态保存

（4）无连接

http请求协议与响应协议

请求协议

请求格式

请求方式：get与post请求

（1）get提交的数据会放在url之后，以？分割url和传输数据，参数之间以&相连

（2）get提交的数据大小有限制（浏览器对url长度有要求）

（3）get与post请求在服务端获取请求数据方式不同

响应协议

响应格式

响应状态码

状态码的职是当客户端向服务器端发送请求时, 返回的请求结果。借助状态码,用户可以知道服务器端是正常理了请求,还是出现了。状态码如200 OK,以3位数字和原因成。数字中的一位指定了响应别,后两位无分。响应别有以5种。

示例

（1）socket服务端，并启动运行

import socket
sk = socket.socket()
sk.bind(("127.0.0.1",8800))
sk.listen(5)

while True:
    print("server waiting...")
    conn,addr = sk.accept()
    data = conn.recv(1024)
    print(data)
    conn.send(b"HTTP/1.1 200 OK\r\n\r\nHello World!")
    """
    发送响应时需要遵守http协议的响应格式，否则在浏览器会报错
    """
    conn.close()

（2）在浏览器输入IP：端口，效果如下

同时在服务器端可以查看接受的数据

b'GET / HTTP/1.1\r\nHost: 127.0.0.1:8800\r\nConnection: keep-alive\r\nCache-Control: max-age=0\r\nUpgrade-Insecure-Requests: 1\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\r\nSec-Fetch-Mode: navigate\r\nSec-Fetch-User: ?1\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\nSec-Fetch-Site: none\r\nAccept-Encoding: gzip, deflate, br\r\nAccept-Language: zh-CN,zh;q=0.9\r\nCookie: csrftoken=MTB0jmt6lcLUJoJJp6yMZ1bSDg6Nj4Nti0uds6mx4uYfbmSZr5s7QXfrtIkv0KvG\r\n\r\n'
server waiting...
b'GET /favicon.ico HTTP/1.1\r\nHost: 127.0.0.1:8800\r\nConnection: keep-alive\r\nSec-Fetch-Mode: no-cors\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\r\nAccept: image/webp,image/apng,image/*,*/*;q=0.8\r\nSec-Fetch-Site: same-origin\r\nReferer: http://127.0.0.1:8800/\r\nAccept-Encoding: gzip, deflate, br\r\nAccept-Language: zh-CN,zh;q=0.9\r\nCookie: csrftoken=MTB0jmt6lcLUJoJJp6yMZ1bSDg6Nj4Nti0uds6mx4uYfbmSZr5s7QXfrtIkv0KvG\r\n\r\n'
server waiting...

可以看到有个favicon.ico这个时图标请求，可以在服务端修改

　　--创建一个html文件

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>test</title>
    <link rel="icon" href="https://www.jd.com/favicon.ico">
</head>
<body>
<h1>Hello World </h1>
</body>
</html>

　　--修改服务端代码

import socket
sk = socket.socket()
sk.bind(("127.0.0.1",8800))
sk.listen(5)

while True:
    print("server waiting...")
    conn,addr = sk.accept()
    data = conn.recv(1024)
    print(data)
    with open("index.html","rb") as f:
        html = f.read()
        conn.send(b"HTTP/1.1 200 OK\r\n\r\n%s"%html)
        """
        发送响应时需要遵守http协议的响应格式，否则在浏览器会报错
        """
        conn.close()

重新运行服务端，输入ip，效果如下

查看服务端接受数据

server waiting...
b'GET / HTTP/1.1\r\nHost: 127.0.0.1:8800\r\nConnection: keep-alive\r\nCache-Control: max-age=0\r\nUpgrade-Insecure-Requests: 1\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\r\nSec-Fetch-Mode: navigate\r\nSec-Fetch-User: ?1\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\nSec-Fetch-Site: none\r\nAccept-Encoding: gzip, deflate, br\r\nAccept-Language: zh-CN,zh;q=0.9\r\nCookie: csrftoken=MTB0jmt6lcLUJoJJp6yMZ1bSDg6Nj4Nti0uds6mx4uYfbmSZr5s7QXfrtIkv0KvG\r\n\r\n'
server waiting...
b''
server waiting...

与form表单结合使用

（1）创建一个form表单文件 input标签中需要添加name在服务端才能接受到数据

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="http://127.0.0.1:8800" method="get">
    <p>username:<input type="text" name="user"></p>
    <p>password:<input type="password" name="pwd"></p>
    <p>sex:
        <input type="radio" name="M">M
        <input type="radio" name="F">F
    </p>

    <p><input type="submit"></p>
</form>
</body>
</html>

（2）浏览器运行，填入数据点击提交

　　--在浏览器的url可以看到对应数据

　　--在服务端接受数据如下

b'GET /?user=abc&pwd=123&M=on HTTP/1.1\r\nHost: 127.0.0.1:8800\r\nConnection: keep-alive\r\nUpgrade-Insecure-Requests: 1\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\r\nSec-Fetch-Mode: navigate\r\nSec-Fetch-User: ?1\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\nSec-Fetch-Site: cross-site\r\nReferer: http://localhost:63342/python/test/form_table.html?_ijt=eekrrf89lamd86eqkq34k3e9tr\r\nAccept-Encoding: gzip, deflate, br\r\nAccept-Language: zh-CN,zh;q=0.9\r\nCookie: csrftoken=MTB0jmt6lcLUJoJJp6yMZ1bSDg6Nj4Nti0uds6mx4uYfbmSZr5s7QXfrtIkv0KvG\r\n\r\n'

（3）将form表单中请求改为post请求

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="http://127.0.0.1:8800" method="post">
    <p>username:<input type="text" name="user"></p>
    <p>password:<input type="password" name="pwd"></p>
    <p>sex:
        <input type="radio" name="M">M
        <input type="radio" name="F">F
    </p>

    <p><input type="submit"></p>
</form>
</body>
</html>

　　--浏览器打开提交

　　返回页面如下：

　　服务端请求如下：

b'POST / HTTP/1.1\r\nHost: 127.0.0.1:8800\r\nConnection: keep-alive\r\nContent-Length: 21\r\nCache-Control: max-age=0\r\nOrigin: http://localhost:63342\r\nUpgrade-Insecure-Requests: 1\r\nContent-Type: application/x-www-form-urlencoded\r\nUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\r\nSec-Fetch-Mode: navigate\r\nSec-Fetch-User: ?1\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\nSec-Fetch-Site: cross-site\r\nReferer: http://localhost:63342/python/test/form_table.html?_ijt=t9i6n11m09bgn87rjt9qn0mnj2\r\nAccept-Encoding: gzip, deflate, br\r\nAccept-Language: zh-CN,zh;q=0.9\r\nCookie: csrftoken=MTB0jmt6lcLUJoJJp6yMZ1bSDg6Nj4Nti0uds6mx4uYfbmSZr5s7QXfrtIkv0KvG\r\n\r\nuser=abc&pwd=123&F=on'

在服务端最后可以得到输入的数据:user=abc&pwd=123&F=on'

posted @ 2019-09-13 14:14 wangzihong 阅读(325) 评论(0) 编辑收藏举报

刷新页面返回顶部