Simple JSON Server 1

gistfile1.py

from twisted.internet import protocol, reactor
from twisted.protocols.basic import LineReceiver
from twisted.internet.endpoints import TCP4ServerEndpoint

import json


class JsonEchoServer(LineReceiver):

    """
    Implements the server-side mechanisms
    """
    
    def connectionMade(self):
        print "Connected!"
        self.sendLine(json.dumps({"from":"server", "message": "connected"}))

    def lineReceived(self, line):
        """Receives a line from our remote"""
        print "Line!"
        m = None
        try:
            m = json.loads(line)
        except json.JSONDecodeError as e:
            self.sendLine(json.dumps(
                {
                    "from": "server",
                    "message": "json parse error {error}".format(e)}
                ))
            print "received non-json-decodable string"
            return

        self.sendLine(json.dumps(
                { "from": "EchoServer", "message": "%s said '%s'" % ( m["from"], m["message"] ) }
            )
        )

class EchoFactory(protocol.Factory):
    def buildProtocol(self, addr):
        e = JsonEchoServer()
        return e


endpoint = TCP4ServerEndpoint(reactor, 1234)
endpoint.listen(EchoFactory())
reactor.run()