HTTP Post does not work

[Thang Nguyen]

Hi everyone,

I am start working on a project require to communicate with a web service (written by another team). I have to use POST HTTP function to request access token with provide username, password and tenant name in JSON format. I use Flatten to JSON to convert a cluster to JSON string for buffer. I have connect URL as it suppose to be. I event use string constant to pass in the JSON directly, but when I ran, it returned header:

HTTP/1.1 401 UNAUTHORIZED
Date: Tue, 15 Dec 2020 04:05:22 GMT
Content-Type: application/json
Content-Length: 44
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: Werkzeug/0.14.1 Python/3.7.2

body:

{"message":"Error in Database connnection"}

The another team told me to test with Postman and it run fine with the same input URL and JSON data. It returns the correct access token.

I am not sure what the different between my labVIEW code and the Postman structure. 

I don't have much experience with HTTP and Web service through so I ask for your inputs.

Thank you very much in advance.

 

 

[LogMAN]

• Do you receive any error at the error output terminal?
• Does the other team see any error in the server logs?
• Did the other team give you any idea about what kind of web service they provide?
  Since the other team suggested Postman, chances are high that they use a RESTful service.
  JKI has a REST API Client library on their website which you could try: JKI HTTP REST API Client for LabVIEW

[Rolf Kalbermatter]

4 hours ago, Thang Nguyen said:

Hi everyone,

I am start working on a project require to communicate with a web service (written by another team). I have to use POST HTTP function to request access token with provide username, password and tenant name in JSON format. I use Flatten to JSON to convert a cluster to JSON string for buffer. I have connect URL as it suppose to be. I event use string constant to pass in the JSON directly, but when I ran, it returned header:

HTTP/1.1 401 UNAUTHORIZED
Date: Tue, 15 Dec 2020 04:05:22 GMT
Content-Type: application/json
Content-Length: 44
Connection: keep-alive
Access-Control-Allow-Origin: *
Server: Werkzeug/0.14.1 Python/3.7.2

body:

{"message":"Error in Database connnection"}

The another team told me to test with Postman and it run fine with the same input URL and JSON data. It returns the correct access token.

I am not sure what the different between my labVIEW code and the Postman structure. 

HTTP Error 401: https://airbrake.io/blog/http-errors/401-unauthorized-error#:~:text=The 401 Unauthorized Error is,client could not be authenticated.&text=Conversely%2C a 401 Unauthorized Error,to provide any such authentication.

Somehow your HTTP server seems to require some authentication and you have not added any header to the query that provides such authentication.

[Thang Nguyen]

@Rolf You are correct about header. I added a header I can find on NI forum as below and it works. Thank you for your input