Objective-C

Azure Service Bus - Unlock Message

See more Azure Service Bus Examples

Shows how to unlock a message for processing by other receivers on a specified queue or subscription. This operation deletes the lock object, causing the message to be unlocked.

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

Objective-C

#import <CkoRest.h>
#import <CkoStringBuilder.h>
#import <NSString.h>

BOOL success = NO;

//  Note: Requires Chilkat v9.5.0.65 or greater.

//  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.
CkoRest *rest = [[CkoRest alloc] init];
BOOL bAutoReconnect = YES;
success = [rest Connect: @"<yournamespace>.servicebus.windows.net" port: [NSNumber numberWithInt: 443] tls: YES autoReconnect: bAutoReconnect];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

//  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.
CkoStringBuilder *sbToken = [[CkoStringBuilder alloc] init];
[sbToken LoadFile: @"qa_data/tokens/serviceBusSas.txt" charset: @"utf-8"];

//  Tell the REST object to use the Azure Shared Access Signature for authorization.
[sbToken Prepend: @"SharedAccessSignature "];
[rest AddHeader: @"Authorization" value: [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 unlock a message, we'll need either the SequenceNumber or MessageId.
//  When the message was 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": 2,
//  	  "EnqueuedSequenceNumber": 3000003,
//  	  "EnqueuedTimeUtc": "Wed, 07 Dec 2016 17:42:48 GMT",
//  	  "Label": "M2",
//  	  "LockToken": "0a13ee8a-be32-4458-89e0-5e1401caa6a0",
//  	  "LockedUntilUtc": "Wed, 07 Dec 2016 18:13:12 GMT",
//  	  "MessageId": "7bea513a6ddb49089e07bfbee26d85bd",
//  	  "SequenceNumber": 3,
//  	  "State": "Active",
//  	  "TimeToLive": 922337203685.47754
//  	}

//  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 unlock a message contained in a subscription.
NSString *topicName = @"gilaMonster";
NSString *subscriptionName = @"feedings";
NSString *messageId = @"7bea513a6ddb49089e07bfbee26d85bd";
NSString *lockToken = @"0a13ee8a-be32-4458-89e0-5e1401caa6a0";

//  Build the path..
CkoStringBuilder *sbPath = [[CkoStringBuilder alloc] init];
[sbPath Append: @"/{topicPath}/subscriptions/{subscriptionName}/messages/{messageId|sequenceNumber}/{lockToken}"];
int numReplaced = [[sbPath Replace: @"{topicPath}" replacement: topicName] intValue];
numReplaced = [[sbPath Replace: @"{subscriptionName}" replacement: subscriptionName] intValue];
numReplaced = [[sbPath Replace: @"{messageId|sequenceNumber}" replacement: messageId] intValue];
numReplaced = [[sbPath Replace: @"{lockToken}" replacement: lockToken] intValue];

//  Add a timeout parameter.
[rest AddQueryParam: @"timeout" value: @"20"];

//  Use the PUT HTTP verb to unlock the message.
CkoStringBuilder *sbResponseBody = [[CkoStringBuilder alloc] init];
success = [rest FullRequestNoBodySb: @"PUT" uriPath: [sbPath GetAsString] sb: sbResponseBody];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

NSLog(@"%@%d",@"Response Status Code = ",[rest.ResponseStatusCode intValue]);

//  Check for a success response.
if ([rest.ResponseStatusCode intValue] != 200) {
    NSLog(@"%@",rest.LastRequestStartLine);
    NSLog(@"%@",rest.LastRequestHeader);
    NSLog(@"%@",[sbResponseBody GetAsString]);
    NSLog(@"%@",@"Failed.");
    return;
}

//  If successful, the response body would be empty..
NSLog(@"%@",@"Success.");