SSE 与乐山 LWM2M 演示服务器

Question

我正在尝试做一个与乐山演示服务器交互的 http api。 我试图在 LWM2M 中处理 OBSERVE，但我需要使用 http 处理通知。 我发现乐山通知使用 SSE。 因此，我尝试使用请求和 sseclient 在 python 中实现 sse 客户端。

这是我的代码：

    response= requests.post(url_request , "format=TLV" , stream= True)    
    client = sseclient.SSEClient(response)
    for event in client.events():
        print(json.loads(event.data))

I tried to run my script but it seems like the stream is not opening and it close immediately without waiting for the answer of the server, even if requests by default implement keep_alive for TCP connection under HTTP and the stream is True.

有人知道为什么吗？

Answer 1

阅读sseclient文档，使用 SSEClient 的正确方法似乎是：

from sseclient import SSEClient
messages = SSEClient('http://example.com/sse_stream/')
for msg in messages:
    do_something_useful(msg)

Reading the answer on Leshan Github, the stream URL for Leshan Server Demo seems to be http://your.leshan.server.org/event?ep=your_device_endpoint_name

所以我尝试了：

from sseclient import SSEClient
messages = SSEClient('http://localhost:8080/event?ep=my_device')
for msg in messages:
    print (msg.event, msg.data)

它对我有用：当我观察 Leshan Client Demo 的温度实例时得到这种结果：

(u'NOTIFICATION', u'{"ep":"my_device","res":"/3303/0","val":{"id":0,"resources":[{"id":5601,"value":-18.9},{"id":5602,"value":31.2},{"id":5700,"value":-18.4},{"id":5701,"value":"cel"}]}}')
(u'COAPLOG', u'{"timestamp":1592296453808,"incoming":true,"type":"CON","code":"POST","mId":29886,"token":"889372029F81C124","options":"Uri-Path: \\"rd\\", \\"reWfKIgPYD\\"","ep":"my_device"}')
(u'COAPLOG', u'{"timestamp":1592296453809,"incoming":false,"type":"ACK","code":"2.04","mId":29886,"token":"889372029F81C124","ep":"my_device"}')
(u'UPDATED', u'{"registration":{"endpoint":"my_device","registrationId":"reWfKIgPYD","registrationDate":"2020-06-16T10:02:25+02:00","lastUpdate":"2020-06-16T10:34:13+02:00","address":"127.0.0.1:44400","lwM2mVersion":"1.0","lifetime":300,"bindingMode":"U","rootPath":"/","objectLinks":[{"url":"/","attributes":{"rt":"\\"oma.lwm2m\\""}},{"url":"/1/0","attributes":{}},{"url":"/3/0","attributes":{}},{"url":"/6/0","attributes":{}},{"url":"/3303/0","attributes":{}}],"secure":false,"additionalRegistrationAttributes":{}},"update":{"registrationId":"reWfKIgPYD","identity":{"peerAddress":{}},"additionalAttributes":{}}}')
(u'COAPLOG', u'{"timestamp":1592296455150,"incoming":true,"type":"NON","code":"2.05","mId":29887,"token":"3998C5DE2588F835","options":"Content-Format: \\"application/vnd.oma.lwm2m+tlv\\" - Observe: 2979","payload":"Hex:e3164563656ce8164408c03199999999999ae815e108c032e66666666666e815e208403f333333333333","ep":"my_device"}')

如果您只对通知感兴趣，只需添加一个if msg.event == 'NOTIFICATION':块。