Python 套接字客户端没有收到任何东西，由 recv.from(datasize) 挂起

Question

我必须制作一个简单的 udp echo 客户端和服务器，目前我的问题是客户端在代码“data，address = sock.recvfrom(dataSize)”处挂起。这是我的客户端和服务器代码（我删除了一些 api 函数，所以它不长）。我尝试了相同的端口和不同的端口，ip也是如此，但我没有收到任何消息。我尝试了一个朋友的原始文件，他的版本可以工作，我在两个文件上都有相同的端口和 ip 以及相同的方法，但它仍然挂在第一行的 echoClient 方法 receiveMSG 上。

echoServerUDP.py

    0<0# : ^
''' 
@echo off
python "%~f0" %*
pause
exit /b 0
'''
#!/usr/bin/env python
import socket
import json

host = '0.0.0.0'
sport = 11111      # own port
dataSize = 1024
ip_adresses = {}


def echo_server():
    receiveSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    receiveSock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    receiveSock.bind((host,sport))
    print("Starting up echo server on %s port %s" % (host, sport))

    while True: 
        print("Waiting to receive message")
        print("Generate a Session ...")
        data, address = receiveSock.recvfrom(dataSize)
        data = data.decode("utf-8")
        if data:
            print("receive data: %s from %s" % (data,address))
            json_object = json.loads(data)
            operation=json_object["operation"]
            if operation == "register":
                register(json_object["name"],json_object["value"],json_object["sid"])
                json_message={"ergebnis":"ok"}
                dump = json.dumps(json_message)
                sendMSG(bytes(dump,encoding="utf-8"),address)
                print("er")
            if operation == "unregister":
                unregister(json_object["name"],json_object["sid"])
            if operation == "query":
                query(json_object["sid"])
            if operation == "reset":
                reset(json_object["sid"])
            
            print("sent %s bytes back to %s" % (data,address))
            
def sendMSG(data,address):
    sendSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sendSock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sendSock.sendto(data,address)
    sendSock.close()


if __name__ == '__main__':
    echo_server()

这里是 echoClientUDP.py

    0<0# : ^
''' 
@echo off
python "%~f0" %*
pause
exit /b 0
'''
#!/usr/bin/env python
import socket
import time
import json
from random import randint

host = '127.0.0.1'
sport = 11111
dataSize = 1024
sid= randint(1,10000)
name=socket.gethostname()
own_ip = socket.gethostbyname(name)

def echo_client():
    sendSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    try:
        json_message = {"operation":"register","name":name,"value":own_ip,"sid":sid}
        dump = json.dumps(json_message)
        print("Sending %s to %s:%s" % (dump,host,sport))
        sendMSG(sendSock, dump)
        
        data = receiveMSG(sendSock)
        if data: 
            print("Received: %s" % data)
    except Exception as err:
        print("Socket error: %s" %str(err))
    finally:
        print("Closing connection to the server")
        sendSock.close()
        
def sendMSG(sendSock, data):
    sendSock.connect((host, sport))
    sendSock.sendall(bytes(data,encoding="utf-8"))

def receiveMSG(sock):
    data, address = sock.recvfrom(dataSize)
    print(data)
    return data
    
if __name__ == '__main__':
    echo_client()

Answer 1

请在某些方面付出更多努力，例如您没有添加任何标题并且变得更加复杂我还创建了一个类似的工作脚本查看并观察该脚本并更改您的脚本

client.py :-

import socket
import sys

HEADER = 64
PORT = 65432
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "!DISCONNECT"
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)

client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect(ADDR)


def send(msg):
    message = msg.encode(FORMAT)
    msg_length = len(message)
    send_length = str(msg_length).encode(FORMAT)
    send_length += b' ' * (HEADER - len(send_length))
    client.send(send_length)
    client.send(message)
    print(client.recv(2048).decode(FORMAT))


def chat():
    while True:
        try:
            a = input()
            if 'quit' in a:
                sys.exit()
            else:
                send(a)
        except Exception as e:
            print(e)
            sys.exit()

chat()

server.py :-

import socket
import threading

HEADER = 64
PORT = 65432
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "Bye"

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind(ADDR)


def handle_client(conn, addr):
    print(f"[NEW CONNECTION] {addr} connected.")

    connected = True
    while connected:
        msg_length = conn.recv(HEADER).decode(FORMAT)
        if msg_length:
            msg_length = int(msg_length)
            msg = conn.recv(msg_length).decode(FORMAT)
            if msg == DISCONNECT_MESSAGE:
                connected = False
                print(f"[{addr}] left")
                

            print(f"[{addr}] {msg}")
            conn.send("Msg received".encode(FORMAT))

    conn.close()


def start():
    server.listen()
    print(f"[LISTENING] Server is listening on {SERVER}")
    while True:
        conn, addr = server.accept()
        thread = threading.Thread(target=handle_client, args=(conn, addr))
        thread.start()
        print(f"[ACTIVE CONNECTIONS] {threading.activeCount() - 1}")


print("[STARTING] server is starting...")
start()

我在这里使用了线程来加快处理速度。

先后台运行server.py，再运行client.py连接服务器。