在 Raspberry PI 和 Android 设备之间建立 TCP 服务器和客户端套接字连接

Question

我在 Raspberry PI 上制作服务器套接字，在 Android 移动设备上制作客户端套接字。 他们可以相互建立连接，并且服务器套接字端出现错误，客户端没有收到服务器端发送的消息。 我的服务器端程序是

import socket
import time
import picamera
import sys

# Start a socket listening for connections on 192.168.0.17:8080
server_socket = socket.socket()
server_socket.bind(('192.168.0.17', 8080))
server_socket.listen(0)
print >> sys.stderr,'Listening'
# Accept a single connection and make a file-like object out of it
while True:
   connection = server_socket.accept()[0].makefile('wb')
   print >> sys.stderr, 'Connected with'
   try:
      print >> sys.stderr, 'going to write'
      connection.write("linked")
      connection.flush()
      print >> sys.stderr, 'Sent message'
      time.sleep(20)
   finally:
      print >> sys.stderr, 'Server socket is going to be closed'
      connection.close()
      server_socket.close()
      print >> sys.stderr, 'Server socket is closed'

打印输出显示服务器socket发送了消息，如下

Listening
Connected with
going to write
Sent message
Server socket is going to be closed
Server socket is closed

错误是

Traceback (most recent call last):
  File "/home/pi/PY_programs/camera_play.py", line 13, in <module>
    connection = server_socket.accept()[0].makefile('wb')
  File "/usr/lib/python2.7/socket.py", line 202, in accept
    sock, addr = self._sock.accept()
  File "/usr/lib/python2.7/socket.py", line 170, in _dummy
    raise error(EBADF, 'Bad file descriptor')
error: [Errno 9] Bad file descriptor

此错误有什么问题以及为什么我没有在客户端收到“链接”消息。 谢谢

Answer 1

finally:
      print >> sys.stderr, 'Server socket is going to be closed'
      connection.close()
      server_socket.close()
      print >> sys.stderr, 'Server socket is closed'

在这里你也关闭了服务器套接字。不要那样做，您需要在循环的下一次迭代中使用 server_socket，以便它可以接受新客户端。