I am a beginner in the API ecosystem. I am using VB.NET to call API. Code used for the same given below:
Try
Dim s As HttpWebRequest
Dim enc As UTF8Encoding
Dim postdata As String
Dim postdatabytes As Byte()
Dim jo As New JObject
jo.Add("apiid", objProp.Text7)
jo.Add("apiData", objProp.Text8)
postdata = jo.ToString()
s = HttpWebRequest.Create(objProp.Text6)
enc = New System.Text.UTF8Encoding()
postdatabytes = enc.GetBytes(postdata)
s.Method = "POST"
s.ContentType = "application/json"
s.ContentLength = postdatabytes.Length
s.Headers.Add("user-name", "MjRKQGU1NypQJkxZYVpCdzJZXnpKVENmIXFGQyN6XkI=")
s.Headers.Add("api-key", "UjMhTDZiUlE1MkhMWmM2RkclJXJhWUJTTWZDeHVEeDQ=")
Using stream = s.GetRequestStream()
stream.Write(postdatabytes, 0, postdatabytes.Length)
End Using
Dim result = s.GetResponse()
Dim responsedata As Stream = result.GetResponseStream
Dim responsereader As StreamReader = New StreamReader(responsedata)
Dim xResponse = responsereader.ReadToEnd
Try
Dim opData = JObject.Parse(xResponse)("apiData").ToString
objProp = JsonConvert.DeserializeObject(Of default_prop)(opData)
Catch ex As Exception
End Try
Catch myerror As OracleException
'Status
objProp.Text5 = "500"
'Failure Response Message
objProp.Text11 = "Internal Server Error..."
db_close()
End Try
My issue is that I could not find the proper syntax to retrieve API Response Status Code from the response. Request your guidance
With some small changes on your code you can do the trick as follow:
'....... other code here
Using stream = s.GetRequestStream()
stream.Write(postdatabytes, 0, postdatabytes.Length)
End Using
Dim result As HttpWebResponse = CType(s.GetResponse(), HttpWebResponse)
Console.WriteLine(result.StatusCode)
Related
I am getting TWO exceptions. The first one in the regular code and the second into the exception handling block.
I have this function (below) that supposed to change user settings in a Web API using PUT method. Everything runs fine until the point that I try to get a response from the web request. Then it raises the first exception (unknown) and when I try to handle the error I get a second exception "Object reference not set to an instance of an object".
As far as I know normally what will cause this error is the attempt of getting a response of an unassigned web request, but in this case it IS assigned and the Uri is valid. All the credentials for authorization are correct too.
This is my code:
Try
Dim webRequest As System.Net.HttpWebRequest
webRequest = System.Net.HttpWebRequest.Create(InternalSettings.APIurl + "/config")
webRequest.Headers("Authorization") = InternalSettings.APIpwd
webRequest.Headers("API-Application-Key") = InternalSettings.APIkey
webRequest.Method = "PUT"
webRequest.ContentType = "application/x-www-form-urlencoded"
Dim postData As String = ""
postData += "SaveAllCustomersData=false"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
Dim dataStream As Stream = webRequest.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
'The next line will raise an unknown exception
Dim myHttpWebResponse As HttpWebResponse = webRequest.GetResponse
Dim responseReader As StreamReader = New StreamReader(myHttpWebResponse.GetResponseStream())
Dim responseData As String = responseReader.ReadToEnd()
responseReader.Close()
webRequest.GetResponse().Close()
Catch ex As WebException
'The next line will raise a "Object reference not set to an instance of an object" exception
Dim resp = New StreamReader(ex.Response.GetResponseStream()).ReadToEnd()
Dim obj = JsonConvert.DeserializeObject(resp)
Return False
End Try
If you are using basic authentification you can try something like this:
Dim strUrl As String = InternalSettings.APIurl + "/config"
Dim request As WebRequest = DirectCast(WebRequest.Create(strUrl), HttpWebRequest)
Dim strResponse As String = ""
Dim byteAuth() As Byte = Encoding.UTF8.GetBytes(InternalSettings.APIkey & ":" & InternalSettings.APIpwd)
Dim strPost As String = "SaveAllCustomersData=false"
Dim bytePost() As Byte = Encoding.UTF8.GetBytes(strPost)
request.ContentType = "application/x-www-form-urlencoded"
request.Method = "PUT"
request.Headers.Add("Authorization", "Basic " & Convert.ToBase64String(byteAuth))
Using sw = New StreamWriter(request.GetRequestStream())
sw.Write(bytePost, 0, bytePost.Length)
sw.Flush()
Using response As HttpWebResponse = request.GetResponse()
Using sr = New StreamReader(response.GetResponseStream())
strResponse = sr.ReadToEnd()
End Using
End Using
End Using
i am try send raw data into PUT method , but i am getting error as "The remote server returned an error: (502) Bad Gateway"
But same data i try to use in Postman Agent, its working.
What i tried
Private Function SendRequest(uri As Uri, jsonDataBytes As Byte(), contentType As String, method As String) As String
Dim req As WebRequest = WebRequest.Create(uri)
req.ContentType = contentType
req.Method = method
req.ContentLength = jsonDataBytes.Length
req.Headers.Add("x-api-key:xxxxxY0tZN55jbXnY05Oxxxxx")
Dim stream = req.GetRequestStream()
stream.Write(jsonDataBytes, 0, jsonDataBytes.Length)
stream.Close()
Dim response = req.GetResponse().GetResponseStream()
Dim reader As New StreamReader(response)
Dim res = reader.ReadToEnd()
reader.Close()
response.Close()
Return res
End Function
Calling function
Dim postdata As String = "[{barcod:A0000041},{barcode:A0000113}]"
Dim data = Encoding.UTF8.GetBytes(postdata)
Dim Uri As New Uri("https://sample.com/xxxxx/xxxxx?funcName=UpdateBaarcode")
Dim result_post = SendRequest(Uri, data, "text/plain", "PUT")
What i missing , pls reply.
Regards,
Aravind
For REST API
I use WebRequest using DirectCast.
It's been so long I can't remember why. TT
Try like the code below.
Private Function SendRequest(uri As Uri, jsonDataBytes As Byte(), contentType As String, method As String) As String
Dim req As HttpWebRequest= DirectCast(WebRequest.Create(uri), HttpWebRequest)
req.ContentType = contentType
req.Method = method
req.ContentLength = jsonDataBytes.Length
req.Headers.Add("x-api-key:xxxxxY0tZN55jbXnY05Oxxxxx")
Dim stream = req.GetRequestStream()
stream.Write(jsonDataBytes, 0, jsonDataBytes.Length)
stream.Close()
Dim response = DirectCast(req.GetResponse(), HttpWebResponse)
Dim reader As New StreamReader(response.GetResponseStream)
Dim res = reader.ReadToEnd()
reader.Close()
response.Close()
Return res
End Function
I need away to disable chaching for my VB.NET code. I've found some hints in C#, but nothing that I can get to work.
Right now, when i send in a request, i'm getting the previous request results.
Here's my code:
Dim responseData As String = ""
Try
Dim cookieJar As New Net.CookieContainer()
Dim hwrequest As Net.HttpWebRequest = Net.WebRequest.Create(URL)
hwrequest.CookieContainer = cookieJar
hwrequest.Accept = "*/*"
hwrequest.AllowAutoRedirect = True
hwrequest.UserAgent = "http_requester/0.1"
hwrequest.Timeout = 60000
hwrequest.Method = method
'hwrequest.CachePolicy = CachePolicy
If hwrequest.Method = "POST" Then
hwrequest.ContentType = "application/x-www-form-urlencoded"
Dim encoding As New Text.ASCIIEncoding() 'Use UTF8Encoding for XML requests
Dim postByteArray() As Byte = encoding.GetBytes(POSTdata)
hwrequest.ContentLength = postByteArray.Length
Dim postStream As IO.Stream = hwrequest.GetRequestStream()
postStream.Write(postByteArray, 0, postByteArray.Length)
postStream.Close()
End If
Dim hwresponse As Net.HttpWebResponse = hwrequest.GetResponse()
If hwresponse.StatusCode = Net.HttpStatusCode.OK Then
Dim responseStream As IO.StreamReader =
New IO.StreamReader(hwresponse.GetResponseStream())
responseData = responseStream.ReadToEnd()
End If
hwresponse.Close()
cookieJar = Nothing
Catch e As Exception
responseData = "An error occurred: " & e.Message
End Try
Return responseData
End Function```
Any help would be appreciated!
What is the best way to issue a http get in VB.net? I want to get the result of a request like
http://89.36.220.56/api.php?photo=urlphoto&point=numberlikes&socks=proxy
Photo = URL Photo
Point = Number
Socks = Proxy
Dim url = "http://89.36.220.56/api.php?photo=urlphoto&point=numberlikes&socks=proxy"
Dim request = DirectCast(WebRequest.Create(url), HttpWebRequest)
Dim response = request.GetResponse()
Dim receiveStream As Stream = response.GetResponseStream()
Dim readStream As New StreamReader(receiveStream, Encoding.UTF8)
Dim data = readStream.ReadToEnd()
response.Close()
readStream.Close()
Here's my code that I am using to send as post to the specified URL.
Dim url = "http://www.abc.com/new/process"
Dim data As String = nvc.ToString
Dim postAddress = New Uri(Url)
Dim request = DirectCast(WebRequest.Create(postAddress), HttpWebRequest)
request.Method = "POST"
request.ContentType = "application/json"
Dim postByteData As Byte() = UTF8Encoding.UTF8.GetBytes(data)
request.ContentLength = postByteData.Length
Using postStream As Stream = request.GetRequestStream()
postStream.Write(postByteData, 0, postByteData.Length)
End Using
Using resp = TryCast(request.GetResponse(), HttpWebResponse)
Dim reader = New StreamReader(resp.GetResponseStream())
result.Response = reader.ReadToEnd()
End Using
Now the problem is I don't get any exception here, but the response I'm supposed to get after posting (success or error) is not coming to my end. The URL is fine, I checked it. Am I sending it the right way?
I believe the issue is that ReadToEnd method on StreamReader internally uses the Length property. This will be null if the server doesn't send a length in the http header. Try using memory stream and a buffer instead:
Dim url = "http://my.posturl.com"
Dim data As String = nvc.ToString()
Dim postAddress = New Uri(url)
Dim request As HttpWebRequest = WebRequest.Create(postAddress)
request.Method = "POST"
request.ContentType = "application/json"
Dim postByteData As Byte() = UTF8Encoding.UTF8.GetBytes(data)
request.ContentLength = postByteData.Length
Using postStream As Stream = request.GetRequestStream()
postStream.Write(postByteData, 0, postByteData.Length)
End Using
Using resp = TryCast(request.GetResponse(), HttpWebResponse)
Dim b As Byte() = Nothing
Using stream As Stream = resp.GetResponseStream()
Using ms As New MemoryStream()
Dim count As Integer = 0
Do
Dim buf As Byte() = New Byte(1023) {}
count = stream.Read(buf, 0, 1024)
ms.Write(buf, 0, count)
Loop While stream.CanRead AndAlso count > 0
b = ms.ToArray()
End Using
End Using
Console.WriteLine("Response: " + Encoding.UTF8.GetString(b))
Console.ReadLine()
End Using