B4X

Cloudfare DNS over HTTPS

See more Cloudfare Examples

Cloudflare offers a DNS over HTTPS resolver at: https://cloudflare-dns.com/dns-query

This example demonstrates how to do a DNS lookup for a domain using Cloudfare's HTTPS resolver.

B4X

'  This example requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

Dim http As ChilkatHttp
http.Initialize("http")

'  Send the following CURL request:   curl -H 'accept: application/dns-json' 'https://cloudflare-dns.com/dns-query?name=chilkat.io&type=A'

http.Accept = "application/dns-json"

Dim url As String = "https://cloudflare-dns.com/dns-query?name=chilkat.io&type=A"

Dim jsonResp As String = http.QuickGetStr(url)
If http.LastMethodSuccess <> True Then
    Log(http.LastErrorText)
    Return
End If


Log("Response Status Code: " & http.LastStatus)

Dim json As ChilkatJsonObject
json.Initialize
json.Load(jsonResp)
json.EmitCompact = False
Log(json.Emit)

If http.LastStatus <> 200 Then
    Log("Failed.")
    Return
End If


'  Sample output...
'  (See the parsing code below..)
'  

'  {
'    "Status": 0,
'    "TC": false,
'    "RD": true,
'    "RA": true,
'    "AD": false,
'    "CD": false,
'    "Question": [
'      {
'        "name": "chilkat.io.",
'        "type": 1
'      }
'    ],
'    "Answer": [
'      {
'        "name": "chilkat.io.",
'        "type": 1,
'        "TTL": 900,
'        "data": "52.25.83.238"
'      }
'    ]
'  }

'  Use this online tool to generate parsing code from sample JSON: 
'  Generate Parsing Code from JSON

Dim Status As Int
Dim TC As Boolean
Dim RD As Boolean
Dim RA As Boolean
Dim AD As Boolean
Dim CD As Boolean
Dim i As Int
Dim count_i As Int
Dim name As String
Dim type As Int
Dim TTL As Int
Dim data As String
Dim ipAddr As String

Status = json.IntOf("Status")
TC = json.BoolOf("TC")
RD = json.BoolOf("RD")
RA = json.BoolOf("RA")
AD = json.BoolOf("AD")
CD = json.BoolOf("CD")
i = 0
count_i = json.SizeOfArray("Question")
Do While i < count_i
    json.I = i
    name = json.StringOf("Question[i].name")
    type = json.IntOf("Question[i].type")
    i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("Answer")
'  The domain name resolves to 1 or more IP addresses..
Do While i < count_i
    json.I = i
    name = json.StringOf("Answer[i].name")
    type = json.IntOf("Answer[i].type")
    TTL = json.IntOf("Answer[i].TTL")
    ipAddr = json.StringOf("Answer[i].data")

    Log("IP Address: " & ipAddr)
    i = i + 1
Loop