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AsyncHTTPClient是 tornado.httpclinet 提供的一個異步http客戶端。使用也比較簡單。與服務進程一樣，AsyncHTTPClient也可以callback和yield兩種使用方式。前者不會返回結果，后者則會返回response。 示例： 1 class AsyncHandler(tornado.web.RequestHandler):
2 @tornado.web.asynchronous
3 def get(self, *args, **kwargs):
4
5 url = 'https://api.github.com/'
6 http_client = tornado.httpclient.AsyncHTTPClient()
7 http_client.fetch(url, self.on_response)
8 self.finish('It works')
9
10 @tornado.gen.coroutine
11 def on_response(self, response):
12 print response.code 同樣，為了獲取response的結果，只需要yield函數。使用yield的時候，handler是需要 tornado.gen.coroutine。 1 class AsyncResponseHandler(tornado.web.RequestHandler):
2 @tornado.web.asynchronous
3 @tornado.gen.coroutine
4 def get(self, *args, **kwargs):
5
6 url = 'https://api.github.com/'
7 http_client = tornado.httpclient.AsyncHTTPClient()
8 response = yield tornado.gen.Task(http_client.fetch, url)
9 print response.code
10 print response.body 如果業務處理并不是在handlers寫的，而是在別的地方，當無法直接使用tornado.gen.coroutine的時候，可以構造請求，使用callback的方式。 1 body = urllib.urlencode(params)
2 req = tornado.httpclient.HTTPRequest(
3 url=url,
4 method='POST',
5 body=body,
6 validate_cert=False)
7
8 http_client.fetch(req, self.handler_response)
9
10 def handler_response(self, response):
11
12 print response.code AsyncHTTPClient中的fetch方法，第一個參數其實是一個HTTPRequest實例對象，因此對于一些和http請求有關的參數，例如method和body，可以使用HTTPRequest先構造一個請求，再扔給fetch方法 1 def getURL():
2 2 # 接口地址
3 3 url = "http://ip:port/Get2"
4 4
5 5
6 6 payload = {"key":"914683196200","timestamp":"2019-07-11 11:27:21","partner_id":"1","sign":"C77CAAA496FE0D385410A"}
7 7 # verify = False 忽略SSH 驗證
8 8
9 9 try:
10 response = requests.post(url, json=payload, timeout=5) # 超時的時候回報錯并重試
11 print(r.json())
12 except ReadTimeout:
13 # 超時異常
14 print('Timeout')
15 return 1
16 except ConnectionError:
17 # 連接異常
18 print('Connection error')
19 return 2
20 except RequestException as e:
21 # 請求異常
22 print('Error')
23 print('str(Exception):\t', str(Exception))
24 print('str(e):\t\t', str(e))
25 print('repr(e):\t', repr(e)) 注意：使用異步，必須tornado.ioloop.IOLoop.instance().start啟動 IOLoop 的實例，啟動事件循環機制，配合非阻塞的 HTTP Server 工作
  callback_async
1 @coroutine
2 def post ( self, url, body, domain=None ) :
3 try :
4 request = AsyncHTTPClient()
5 response = yield request.fetch(url, method="POST", body=body)
6 logger.info("url: {0} code: {1}".format(url, response.code))
7 self.retry()
8 raise Return(True)
9 except Return :
10 pass
11 except Exception as e :
12 print('str(Exception):\t', str(Exception))
13 print('str(e):\t\t', str(e))
14 print('repr(e):\t', repr(e))
15 print('e.message:\t', e.message)
16 logger.exception("url: {0}".format(url))
17 self.push(uri, body, domain)
18 self.reload_domain()
19 raise Return(False)
20
21
22 @coroutine
23 def post_callback ( self, url, body, domain=None, call_back=None, error_back=None, retry_times=3 ) :
24 try :
25 request = AsyncHTTPClient()
26
27 response = yield request.fetch(url, method="POST", body=body)
28 logger.info("url: {0} code: {1}".format(url, response.code))
29 if call_back :
30 call_back(response)
31 except Exception as e :
32 print('str(Exception):\t', str(Exception))
33 print('str(e):\t\t', str(e))
34 print('repr(e):\t', repr(e))
35 print('e.message:\t', e.message)
36 if retry_times > 0 :
37 logger.info("url: {0} retry: {1}".format(url, retry_times))
38 retry_times -= 1
39 IOLoop.instance().call_later(1, self.post_callback, uri, body, domain, call_back, error_back,
40 retry_times)
41 else :
42 logger.exception("url: {0}".format(url))
43 if error_back :
44
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