獲取Haskell中網頁的狀態代碼

Question

我試圖找到一種方法來檢查網頁是否存在於Haskell中。服務器只有HTTP2/HTTPS，我試圖檢查頁面是否存在於servant應用程序中。

是否有任何Haskell包具有良好的文檔來檢查狀態碼是200還是404？並使用強大的HTTPS和HTTP2服務器？ （握手失敗（Error_Protocol（「期待服務器你好，得到警報：[（AlertLevel_Fatal，HandshakeFailure）]」，True，HandshakeFailure）））這是我目前與http-conduit，但我收到奇怪的異常（TlsExceptionHostPort 「thibaud.dauce.fr」443和StatusCodeException）。

... other imports 
import qualified Network.HTTP.Conduit as HTTP 

... other types 
type AppM = ReaderT Config (EitherT ServantErr IO) 

newComment :: String -> OneComment -> AppM Int64 
newComment baseUrl oneComment = do 
    time <- liftIO getCurrentTime 
    response <- HTTP.withManager $ \manager -> do 
     request <- HTTP.parseUrl $ url oneComment 
     HTTP.httpLbs request manager 
    case (statusIsSuccessful $ HTTP.responseStatus response, startswith baseUrl (url oneComment)) of 
     (_, False) -> return 0 
     (True, True) -> do 
      theNewComment <- runDb $ insert $ Comment (url oneComment) (content oneComment) time 
      return $ fromSqlKey theNewComment 
     _ -> return 0 

Answer 1

使用wreq

{-# LANGUAGE OverloadedStrings #-} 

import Network.Wreq 
import Control.Lens 
import Control.Exception as E 
import Network.HTTP.Client (HttpException) 

test1 = do 
    r <- get "https://httpbin.org/get" 
    print $ r ^. responseStatus . statusCode 

-- throws an exception 
test2 = do 
    r <- get "https://www.google123123.com" 
    print $ r ^. responseStatus . statusCode 

testUrl url = do 
    r <- get url 
    return $ r ^. responseStatus . statusCode 

-- catching the exception 
test3 = do 
    st <- testUrl "https://www.google123123123.com" `E.catch` handler 
    print st 
    where 
    handler :: HttpException -> IO Int 
    handler _ = return 999