javascript - Python 套接字脚本 <-> HTML 客户端

Question

使用以下代码，我可以在我的 Raspberry Pi 中创建一个套接字服务器，如果通过套接字客户端(如 Android 应用程序)访问它，它会工作得很好。

但是，我想将 websocket 功能集成到我的网站，所以我开始尝试通过 HTML 文本框发送一个简单的消息，python 脚本将接收并回复。

问题是我无法获取 HTML 代码来打开、发送并保持打开套接字以进行通信。我确认 html 客户端连接到 python 但无法获取数据，因为连接似乎已关闭。

Python代码

#!/usr/bin/env python

#python3
# https://pythonprogramming.net/client-server-python-sockets/

import socket               # Websocket 
import sys                  # 
from _thread import *       # Used for multi-threading      The thread module has been renamed to _thread in Python 3.
import time                 # Used to create delays

# ******* WEBSOCKET VARIABLES *******
numberClients = 0
host = ''
PORT = 2223
# ******* WEBSOCKET VARIABLES *******

# ************************** FUNCTIONS **************************
def threaded_client(conn,address):      # receive as parameters, the connection object (conn), and the address object that contains the ip and port
    global numberClients
    conn.send(str.encode('Welcome, type your info\n'))  # data should be bytes
    numberClients = numberClients + 1

    #           CHECK USER USING PASSWORD OR SOMETHING
    if ("192.168" in str(address[0])):
        print ("     VALID CLIENT!!")

        while True:
            data = conn.recv(2048)
            if (data):
                reply = "" + 'Server output: '+ data.decode('utf-8').rstrip() + "\n"
                print(str(address[0]) + " - Clients(" + str(numberClients) + ") -> Data received: >" + data.decode('utf-8').rstrip() + "<")
            if not data:
                #print("no data")
                #break
                foo = 2
            try:
                conn.sendall(str.encode(reply))     # data should be bytes
            except Exception as e:
                foo = 1
        print("Thread connection closed by client: " + address[0])
        conn.close()
        numberClients = numberClients - 1

    else:
        print ("     INVALID CLIENT -> Thread connection closed by USER VALIDATION: " + address[0])
        conn.close()
        numberClients = numberClients - 1
# ************************** FUNCTIONS **************************




# ************************** SETUP **************************
print ("\n----------- Starting Websocket Python Program -----------\n")

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)   # "s" here is being returned a "socket descriptor" by socket.socket.
print(s)

# we are simply attempeting to bind a socket locally, on PORT 5555.
try:
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)         # reuse the port number (in case we just got an error and port was not freed)
    s.bind((host, PORT))                # server side - take IN connections
    print ("Server started on port " + str(PORT))
except socket.error as e:
    print(str(e))
    print('Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1])
    #sys.exit()
print('Socket bind complete')

s.listen(5)     # the "5" stands for how many incoming connections we're willing to queue before denying any more.

print('Waiting for a connection.')
# ************************** SETUP **************************



# ************************** MAIN LOOP **************************
while True:
    conn, addr = s.accept()         # code will stop here whilst waiting for a new connection. Old connections will be running in the threads
    print('Connected to: '+addr[0]+':'+str(addr[1]))

    start_new_thread(threaded_client,(conn,addr))   
# ************************** MAIN LOOP **************************

我尝试过的许多 HTML 代码之一:

  <script type="text/javascript">
     function WebSocketTest()
     {
        if ("WebSocket" in window)
        {
           alert("WebSocket is supported by your Browser!");

           // Let us open a web socket
           var ws = new WebSocket("ws://192.168.1.20:5252/echo");
           ws.onopen = function()
           {
              // Web Socket is connected, send data using send()
              ws.send("133:L1");
              alert("Message is sent...");
           };

           ws.onmessage = function (evt) 
           { 
              var received_msg = evt.data;
              alert("Message is received...");
           };

           ws.onclose = function()
           { 
              // websocket is closed.
              alert("Connection is closed..."); 
           };
        }

        else
        {
           // The browser doesn't support WebSocket
           alert("WebSocket NOT supported by your Browser!");
        }
     }
  </script>
      </head>    <body>

  <div id="sse">
     <a href="javascript:WebSocketTest()">Run WebSocket</a>
  </div>
      </body> </html>

如您所见，一切正常: - 不止一个客户端可以连接 - 从 Android 应用程序连接的客户端可以发送和接收消息并保持连接打开 - 接受了 html 客户端，但没有发送消息

Answer 1

这不是您使用 Python 创建的 Websocket 应用程序，而是一个套接字应用程序。 Websocket 是 HTTP 之上的协议(protocol)，它位于 TCP 之上，TCP 是您在 Python 应用程序中使用的实际套接字。要使用 python 创建 Websockets 服务器，您可以尝试 websockets图书馆。

有关差异的更多详细信息，请参阅 Difference between socket and websocket?或 Differences between TCP sockets and web sockets, one more time为了区别。对于服务器代码，请参阅 https://stackoverflow.com/questions/5839054/websocket-server-in-python .