我想实现一个TCP / IP网络客户端应用程序，该应用程序将请求发送到Python
SocketServer，并期望得到响应。我从正式的Python
SocketServer示例代码开始：

server.py:

#!/usr/bin/env python
# encoding: utf-8

import SocketServer

class MyTCPHandler(SocketServer.StreamRequestHandler):

    def handle(self):
        request  = self.rfile.readline().strip()
        print "RX [%s]: %s" % (self.client_address[0], request)

        response = self.processRequest(request)

        print "TX [%s]: %s" % (self.client_address[0], response)
        self.wfile.write(response)

    def processRequest(self, message):
        if   message == 'request type 01':
            return 'response type 01'
        elif message == 'request type 02':
            return 'response type 02'

if __name__ == "__main__":
    server = SocketServer.TCPServer(('localhost', 12345), MyTCPHandler)
    server.serve_forever()

client.py:

#!/usr/bin/env python
# encoding: utf-8

import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

try:
    sock.connect(('127.0.0.1', 12345))

    data = 'request type 01'
    sent = sock.sendall(data + '\n')
    if sent == 0:
        raise RuntimeError("socket connection broken")

    received = sock.recv(1024)
    print "Sent:     {}".format(data)
    print "Received: {}".format(received)

    data = 'request type 02'
    sent = sock.sendall(data + '\n')
    if sent == 0:
        raise RuntimeError("socket connection broken")

    received = sock.recv(1024)
    print "Sent:     {}".format(data)
    print "Received: {}".format(received)

except Exception as e:
    print e

finally:
    sock.close()

server.py 输出：

RX [127.0.0.1]: request type 01
TX [127.0.0.1]: response type 01

client.py 输出：

Sent:     request type 01
Received: response type 01
[Errno 54] Connection reset by peer

怎么了？似乎服务器正在关闭连接。我如何使其保持打开状态？

注意：这是C ++ /
Qt的后续问题：QTcpSocket在读取后不会写入

更新（在 abarnert的回答之后）：

我从中SocketServer.StreamRequestHandler得到的不是最新的设计，虽然它允许我通过网络进行连接，但是它并不能真正为我提供所有与TCP
/ IP相关的方面的支持，而这些方面需要我付诸实施。通讯。

这已在Python
3中使用asyncio解决，但由于该项目在Python
2中进行，因此这不是一个选择。因此，我已经在Twisted中实现了上述服务器和客户端：

server.py:

#!/usr/bin/env python
# encoding: utf-8

from twisted.internet.protocol import Factory
from twisted.protocols.basic import LineReceiver
from twisted.internet import reactor

class SimpleProtocol(LineReceiver):

    def connectionMade(self):
        print 'connectionMade'

    # NOTE: lineReceived(...) doesn't seem to get called

    def dataReceived(self, data):
        print 'dataReceived'
        print 'RX: %s' % data

        if   data == 'request type 01':
            response = 'response type 01'
        elif data == 'request type 02':
            response = 'response type 02'
        else:
            response = 'unsupported request'

        print 'TX: %s' % response
        self.sendLine(response)

class SimpleProtocolFactory(Factory):

    def buildProtocol(self, addr):
        return SimpleProtocol()

reactor.listenTCP(12345, SimpleProtocolFactory(), interface='127.0.0.1')
reactor.run()

client.py:

#!/usr/bin/env python
# encoding: utf-8

from twisted.internet import reactor
from twisted.internet.protocol import Protocol
from twisted.internet.endpoints import TCP4ClientEndpoint, connectProtocol

class SimpleClientProtocol(Protocol):
    def sendMessage(self, msg):
        print "[TX]: %s" % msg
        self.transport.write(msg)

def gotProtocol(p):
    p.sendMessage('request type 01')
    reactor.callLater(1, p.sendMessage, 'request type 02')
    reactor.callLater(2, p.transport.loseConnection)

point = TCP4ClientEndpoint(reactor, '127.0.0.1', 12345)
d = connectProtocol(point, SimpleClientProtocol())
d.addCallback(gotProtocol)
reactor.run()

客户端不会关闭，但是直到CTRL+闲置C。Twisted可能要花点时间才能动手，但对于手头的工作，显然使用一个经过测试和尝试的框架比亲自完成所有这些基础工作更为合理。

注意： 这在Twisted
XmlStream中继续：如何连接到事件？

def handle(self):
    try:
        while True:
            request  = self.rfile.readline()
            if not request:
                break
            request = request.rstrip()
            print "RX [%s]: %s" % (self.client_address[0], request)

            response = self.processRequest(request)

            print "TX [%s]: %s" % (self.client_address[0], response)
            self.wfile.write(response + '\n')
    except Exception as e:
        print "ER [%s]: %r" % (self.client_address[0], e)
    print "DC [%s]: disconnected" % (self.client_address[0])

Sent:     request type 01
Received: resp
Sent:     request type 02
Received: onse type 01
response typ