网络编程中的粘包问题的解决方案

粘包问题的本质是，在TCP协议下，客户端/服务端将两次发送的内容认为是一次传输所引起的问题，以下是粘包问题的相应代码：

1. 服务端

import socket
import subprocess
import struct
import json

service = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
service.bind(('127.0.0.1', 8080))
service.listen(5)
# print('start....')
while True:
    conn, addr = service.accept()
    print(addr)
    while True:
        try:
            cmd = conn.recv(1024)
            obj = subprocess.Popen(cmd.decode('utf-8'),
                                   shell=True,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE)
            stdout = obj.stdout.read()
            stderr = obj.stderr.read()
            header_dict = {'header_size': len(stderr) + len(stdout),
                           'name': 'file_name',
                           'md5':'hhdjfjjkioiuiuywe'}

            header_json = json.dumps(header_dict)
            header_bytes = header_json.encode( 'utf-8')
            num = len(header_bytes)
            conn.send(struct.pack('i', num))


            # total_size = len(stderr) + len(stdout)
            # header = struct.pack('i', total_size)
            conn.send(header_bytes)
            conn.send(stdout)
            conn.send(stderr)
        except Exception:
            break
    conn.close()
service.close()

　　2.客户端

from socket import *
import struct
import json

client=socket(AF_INET,SOCK_STREAM)
client.connect(('127.0.0.1',8080))
# print(client)

while True:
    cmd=input('>>>: ').strip()
    if not cmd:continue
    client.send(cmd.encode('utf-8'))
    #1、先收报头的长度
    header_size=struct.unpack('i',client.recv(4))[0]

    #2、接收报头
    header_bytes=client.recv(header_size)

    #3、解析报头
    header_json=header_bytes.decode('utf-8')
    header_dic=json.loads(header_json)
    print(header_dic)

    total_size=header_dic[ 'total_size']
    # print(total_size) #1025
    #4、根据报头内的信息，收取真实的数据

    recv_size=0
    res=b''
    while recv_size < total_size:
        recv_data=client.recv(1024)
        res+=recv_data
        recv_size+=len(recv_data)

    print(res.decode('gbk'))
client.close()