Python套接字客户端未收到任何信息，由recv.fromdatasize挂起

问题描述

我必须制作一个简单的udp echo客户端和服务器，当前我的问题是客户端将自己挂在代码“数据，地址= sock.recvfrom（dataSize）”上。这是我的客户端和服务器代码（我删除了一些api函数，所以时间不长）。我尝试了相同的端口和不同的端口，并且与ip相同，但是我没有收到任何消息。我从一个朋友那里尝试了原始文件，并且他的版本起作用了，两个文件上都有相同的端口和ip以及相同的方法，但是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,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()

解决方法

请在某些方面加倍努力，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，请查看并观察该脚本并对您的脚本进行更改

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()

并且我在这里使用了线程处理来使过程更快。

首先在后台运行server.py，然后运行client.py连接到服务器。