Question

我正在尝试编写一些测试用例，通过websockets创建客户端来评估服务器的响应。我正在使用高速公路来建立连接。但是，我似乎无法向服务器发送消息，因为我需要协议类的当前活动实例才能运行sendMessage。这是代码：

class SlowSquareClientProtocol(WebSocketClientProtocol):

    def onOpen(self):      
        print "Connection established"

    def onMessage(self, payload, isBinary):
        if not isBinary:
            res = json.loads(payload.decode('utf8'))
            print("Result received: {}".format(res))
            self.sendClose()

    def onClose(self, wasClean, code, reason):
        if reason:
            print(reason)
        reactor.stop()

class NLVRTR(TestFixture,SlowSquareClientProtocol):
    @classmethod
    def setUpClass(self):        
        log.startLogging(sys.stdout)
        factory = WebSocketClientFactory(u"ws://someURL:8078")
        factory.protocol = SlowSquareClientProtocol
        reactor.connectTCP("someURL", 8078, factory)
        wsThread = threading.Thread(target = reactor.run, 
            kwargs={'installSignalHandlers':0})
        wsThread.start()

    def test_00_simple(self):
        WSJsonFormatter = WSformat()
        x = WSJsonFormatter.formatGetInfo(2)
        self.sendMessage(json.dumps(x).encode('utf8'))
        print("Request to square {} sent.".format(x))

所以只是详细说明，我在setUpClass方法中启动了客户端，我正在尝试在test_00_simple中发送一些消息。但是，我似乎得到了这样的错误

AttributeError: 'NLVRTR' object has no attribute 'state'

State应该是WebSocketClientProtoco中定义的属性。如果我将sendmessage放在onOpen方法中，一切正常，但除了SlowSquareClientProtocol类之外，我无法从其他任何地方调用它。在高速公路的文件中，有人提到

Whenever a new client connects to the server, a new protocol instance will be created

我认为这是问题所在，它创建了一个新的协议实例，而sendmessage方法正在使用该实例。由于我没有在slowsquare ...类中调用它，因此当客户端连接错误时，sendmessage从未接触到这个新创建的协议。我的问题是，有没有办法在客户端连接后通过我的代码获取新创建的实例？

Answer 1

I found a stupid way around this by using garbage collector to retrieve the instance like so

#Used to get the instance of the protocol
def getIn(self):
    for obj in gc.get_objects():
        if isinstance(obj, SlowSquareClientProtocol):
            protocol = obj
    return protocol

def test_00_startSession(self):
    WSJsonFormatter = WSformat()
    x = WSJsonFormatter.formatCreateSession("eng-USA", sessionId = "837ab900-912e-11e6-b83e-3f30a2b99389")
    SlowSquareClientProtocol.sendMessage(self.getIn(),json.dumps(x).encode('utf8'))
    print("Request {} sent.".format(x))

So i searched all instances which have the name of the class I am looking for, and then pass it in the sendmessage method. I am still opened to other simpler suggestions :)

如何在python中获取类的实例

1 个答案: