B4X

Azure Service Bus - Delete Message

See more Azure Service Bus Examples

Deletes a message from a queue or subscription.

For more information, see https://docs.microsoft.com/en-us/rest/api/servicebus/unlock-message

B4X

Dim success As Boolean = False

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

'  Make the initial connection.
'  A single REST object, once connected, can be used for many Azure Service Bus REST API calls.
'  The auto-reconnect indicates that if the already-established HTTPS connection is closed,
'  then it will be automatically re-established as needed.
Dim rest As ChilkatRest
rest.Initialize("rest")
Dim bAutoReconnect As Boolean = True
success = rest.Connect("<yournamespace>.servicebus.windows.net", 443, True, bAutoReconnect)
If success <> True Then
    Log(rest.LastErrorText)
    Return
End If


'  Let's load a previously computed SAS token and use it.
'  See Azure Shared Access Signature for an example to genenerate an Azure SAS token.
Dim sbToken As ChilkatStringBuilder
sbToken.Initialize
sbToken.LoadFile("qa_data/tokens/serviceBusSas.txt", "utf-8")

'  Tell the REST object to use the Azure Shared Access Signature for authorization.
sbToken.Prepend("SharedAccessSignature ")
rest.AddHeader("Authorization", sbToken.GetAsString)

'  ----------------------------------------------------------------------------------------------
'  The code above this comment could be placed inside a function/subroutine within the application
'  because the connection does not need to be made for every request.  Once the connection is made
'  the app may send many requests..
'  ----------------------------------------------------------------------------------------------

'  To delete a message, we'll need either the SequenceNumber or MessageId.
'  When the message was peek-locked, the SequenceNumber and MessageId of the locked message
'  was returned in the HTTP response header named "BrokerProperties, which contained
'  JSON such as the following:
'  
'  	{
'  	  "DeliveryCount": 1,
'  	  "EnqueuedSequenceNumber": 3000004,
'  	  "EnqueuedTimeUtc": "Wed, 07 Dec 2016 17:42:48 GMT",
'  	  "Label": "M3",
'  	  "LockToken": "6eeee205-e541-4cb6-95fb-4c81da5f6858",
'  	  "LockedUntilUtc": "Thu, 08 Dec 2016 00:57:32 GMT",
'  	  "MessageId": "e8028116d63c43f191577f2789b1cca7",
'  	  "SequenceNumber": 4,
'  	  "State": "Active",
'  	  "TimeToLive": 922337193600
'  	}
'  
'  
'  The path for unlocking a message is constructed as follows, depending on
'  whether it is a message on a queue or subscription:
'  
'  (for a queue)
'  /{queuePath}/messages/{messageId|sequenceNumber}/{lockToken}
'  
'  (for a subscription)
'  /{topicPath}/subscriptions/{subscriptionName}/messages/{messageId|sequenceNumber}/{lockToken}

'  This example will build a path to delete a message contained in a subscription.
Dim topicName As String = "gilaMonster"
Dim subscriptionName As String = "feedings"
Dim messageId As String = "e8028116d63c43f191577f2789b1cca7"
Dim lockToken As String = "6eeee205-e541-4cb6-95fb-4c81da5f6858"

'  Build the path..
Dim sbPath As ChilkatStringBuilder
sbPath.Initialize
sbPath.Append("/{topicPath}/subscriptions/{subscriptionName}/messages/{messageId|sequenceNumber}/{lockToken}")
Dim numReplaced As Int = sbPath.Replace("{topicPath}", topicName)
numReplaced = sbPath.Replace("{subscriptionName}", subscriptionName)
numReplaced = sbPath.Replace("{messageId|sequenceNumber}", messageId)
numReplaced = sbPath.Replace("{lockToken}", lockToken)

'  Add a timeout parameter.
rest.AddQueryParam("timeout", "20")

'  Use the DELETE HTTP verb to delete the message.
Dim sbResponseBody As ChilkatStringBuilder
sbResponseBody.Initialize
success = rest.FullRequestNoBodySb("DELETE", sbPath.GetAsString, sbResponseBody)
If success <> True Then
    Log(rest.LastErrorText)
    Return
End If


Log("Response Status Code = " & rest.ResponseStatusCode)

'  Check for a success response.
If rest.ResponseStatusCode <> 200 Then
    Log(rest.LastRequestStartLine)
    Log(rest.LastRequestHeader)
    Log(sbResponseBody.GetAsString)
    Log("Failed.")
    Return
End If


'  If successful, the response body would be empty..
Log("Success.")