TCP协议的粘包现象和解决方法

# 粘包现象

# server
import socket

sk = socket.socket()
sk.bind(('127.0.0.1', 8005))
sk.listen()

conn, addr = sk.accept()
conn.send(b'123')
conn.send(b'123')

# client
import time
import socket

sk = socket.socket()

sk.connect(('127.0.0.1', 8005))

time.sleep(5)
msg1 = sk.recv(1024).decode('utf-8')
msg2 = sk.recv(1024).decode('utf-8')
print(msg1)
print(msg2)

# 客户端接收到的信息，两条黏在了一起
# 123123
#
# 这就是粘包现象

解决方法：

# 利用struct模块
# server
import struct
import socket

sk = socket.socket()
sk.bind(('127.0.0.1', 8005))
sk.listen()

def func(msg):
msg = msg
len_msg = len(msg)
struct_msg = struct.pack('i', len_msg)
conn.send(struct_msg)
conn.send(msg)

conn, addr = sk.accept()

msg1 = '这是第一条信息'.encode('utf-8')
msg2 = '这是第二条信息'.encode('utf-8')

func(msg1)
func(msg2)

# client
import struct
import socket
import time

sk = socket.socket()
sk.connect(('127.0.0.1', 8005))

time.sleep(10)

def func(sk):
struct_msg = sk.recv(4)
struct_msg = struct.unpack('i', struct_msg)[0]
msg = sk.recv(int(struct_msg)).decode('utf-8')
return msg

print(func(sk))
print(func(sk))