Subscribe with custom attributes

  namespace 
  
 pubsub 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 pubsub 
 ; 
 auto 
  
 sample 
  
 = 
  
 []( 
 pubsub 
 :: 
 Subscriber 
  
 subscriber 
 ) 
  
 { 
  
 return 
  
 subscriber 
 . 
 Subscribe 
 ( 
  
 [&]( 
 pubsub 
 :: 
 Message 
  
 const 
&  
 m 
 , 
  
 pubsub 
 :: 
 AckHandler 
  
 h 
 ) 
  
 { 
  
 std 
 :: 
 cout 
 << 
 "Received message with attributes: 
 \n 
 " 
 ; 
  
 for 
  
 ( 
 auto 
&  
 kv 
  
 : 
  
 m 
 . 
 attributes 
 ()) 
  
 { 
  
 std 
 :: 
 cout 
 << 
 "  " 
 << 
 kv 
 . 
 first 
 << 
 ": " 
 << 
 kv 
 . 
 second 
 << 
 " 
 \n 
 " 
 ; 
  
 } 
  
 std 
 :: 
 move 
 ( 
 h 
 ). 
 ack 
 (); 
  
 PleaseIgnoreThisSimplifiesTestingTheSamples 
 (); 
  
 }); 
 }; 
 

  using 
  
  Google.Cloud.PubSub.V1 
 
 ; 
 using 
  
 System 
 ; 
 using 
  
 System.Collections.Generic 
 ; 
 using 
  
 System.Threading 
 ; 
 using 
  
 System.Threading.Tasks 
 ; 
 public 
  
 class 
  
 PullMessagesWithCustomAttributesAsyncSample 
 { 
  
 public 
  
 async 
  
 Task<List<PubsubMessage> 
>  
 PullMessagesWithCustomAttributesAsync 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 subscriptionId 
 , 
  
 bool 
  
 acknowledge 
 ) 
  
 { 
  
  SubscriptionName 
 
  
 subscriptionName 
  
 = 
  
  SubscriptionName 
 
 . 
  FromProjectSubscription 
 
 ( 
 projectId 
 , 
  
 subscriptionId 
 ); 
  
  SubscriberClient 
 
  
 subscriber 
  
 = 
  
 await 
  
  SubscriberClient 
 
 . 
  CreateAsync 
 
 ( 
 subscriptionName 
 ); 
  
 var 
  
 messages 
  
 = 
  
 new 
  
 List<PubsubMessage> 
 (); 
  
 Task 
  
 startTask 
  
 = 
  
 subscriber 
 . 
  StartAsync 
 
 (( 
  PubsubMessage 
 
  
 message 
 , 
  
 CancellationToken 
  
 cancel 
 ) 
  
 = 
>  
 { 
  
 messages 
 . 
 Add 
 ( 
 message 
 ); 
  
 string 
  
 text 
  
 = 
  
 message 
 . 
 Data 
 . 
 ToStringUtf8 
 (); 
  
 Console 
 . 
 WriteLine 
 ( 
 $"Message {message.MessageId}: {text}" 
 ); 
  
 if 
  
 ( 
 message 
 . 
 Attributes 
  
 != 
  
 null 
 ) 
  
 { 
  
 foreach 
  
 ( 
 var 
  
 attribute 
  
 in 
  
 message 
 . 
 Attributes 
 ) 
  
 { 
  
 Console 
 . 
 WriteLine 
 ( 
 $"{attribute.Key} = {attribute.Value}" 
 ); 
  
 } 
  
 } 
  
 return 
  
 Task 
 . 
 FromResult 
 ( 
 acknowledge 
  
 ? 
  
  SubscriberClient 
 
 . 
  Reply 
 
 . 
  Ack 
 
  
 : 
  
  SubscriberClient 
 
 . 
  Reply 
 
 . 
  Nack 
 
 ); 
  
 }); 
  
 // Run for 7 seconds. 
  
 await 
  
 Task 
 . 
 Delay 
 ( 
 7000 
 ); 
  
 await 
  
 subscriber 
 . 
  StopAsync 
 
 ( 
 CancellationToken 
 . 
 None 
 ); 
  
 // Lets make sure that the start task finished successfully after the call to stop. 
  
 await 
  
 startTask 
 ; 
  
 return 
  
 messages 
 ; 
  
 } 
 } 
 

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "time" 
  
 "cloud.google.com/go/pubsub/v2" 
 ) 
 func 
  
 pullMsgsCustomAttributes 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 projectID 
 , 
  
 subID 
  
 string 
 ) 
  
 error 
  
 { 
  
 // projectID := "my-project-id" 
  
 // subID := "my-sub" 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 pubsub 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 projectID 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "pubsub.NewClient: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 // client.Subscriber can be passed a subscription ID (e.g. "my-sub") or 
  
 // a fully qualified name (e.g. "projects/my-project/subscriptions/my-sub"). 
  
 // If a subscription ID is provided, the project ID from the client is used. 
  
 sub 
  
 := 
  
 client 
 . 
 Subscriber 
 ( 
 subID 
 ) 
  
 // Receive messages for 10 seconds, which simplifies testing. 
  
 // Comment this out in production, since `Receive` should 
  
 // be used as a long running operation. 
  
 ctx 
 , 
  
 cancel 
  
 := 
  
 context 
 . 
 WithTimeout 
 ( 
 ctx 
 , 
  
 10 
 * 
 time 
 . 
 Second 
 ) 
  
 defer 
  
 cancel 
 () 
  
 // Receive blocks until the context is cancelled or an error occurs. 
  
 err 
  
 = 
  
 sub 
 . 
 Receive 
 ( 
 ctx 
 , 
  
 func 
 ( 
 _ 
  
 context 
 . 
 Context 
 , 
  
 msg 
  
 * 
 pubsub 
 . 
 Message 
 ) 
  
 { 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "Got message :%q\n" 
 , 
  
 string 
 ( 
 msg 
 . 
 Data 
 )) 
  
 fmt 
 . 
 Fprintln 
 ( 
 w 
 , 
  
 "Attributes:" 
 ) 
  
 for 
  
 key 
 , 
  
 value 
  
 := 
  
 range 
  
 msg 
 . 
 Attributes 
  
 { 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "%s = %s\n" 
 , 
  
 key 
 , 
  
 value 
 ) 
  
 } 
  
 msg 
 . 
 Ack 
 () 
  
 }) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "sub.Receive: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 return 
  
 nil 
 } 
 

  import 
  
 com.google.cloud.pubsub.v1. AckReplyConsumer 
 
 ; 
 import 
  
 com.google.cloud.pubsub.v1. MessageReceiver 
 
 ; 
 import 
  
 com.google.cloud.pubsub.v1. Subscriber 
 
 ; 
 import 
  
 com.google.pubsub.v1. ProjectSubscriptionName 
 
 ; 
 import 
  
 com.google.pubsub.v1. PubsubMessage 
 
 ; 
 import 
  
 java.util.concurrent.TimeUnit 
 ; 
 import 
  
 java.util.concurrent.TimeoutException 
 ; 
 public 
  
 class 
 SubscribeWithCustomAttributesExample 
  
 { 
  
 public 
  
 static 
  
 void 
  
 main 
 ( 
 String 
 ... 
  
 args 
 ) 
  
 throws 
  
 Exception 
  
 { 
  
 // TODO(developer): Replace these variables before running the sample. 
  
 String 
  
 projectId 
  
 = 
  
 "your-project-id" 
 ; 
  
 String 
  
 subscriptionId 
  
 = 
  
 "your-subscription-id" 
 ; 
  
 subscribeWithCustomAttributesExample 
 ( 
 projectId 
 , 
  
 subscriptionId 
 ); 
  
 } 
  
 public 
  
 static 
  
 void 
  
 subscribeWithCustomAttributesExample 
 ( 
 String 
  
 projectId 
 , 
  
 String 
  
 subscriptionId 
 ) 
  
 { 
  
  ProjectSubscriptionName 
 
  
 subscriptionName 
  
 = 
  
  ProjectSubscriptionName 
 
 . 
 of 
 ( 
 projectId 
 , 
  
 subscriptionId 
 ); 
  
 // Instantiate an asynchronous message receiver. 
  
  MessageReceiver 
 
  
 receiver 
  
 = 
  
 ( 
 PubsubMessage 
  
 message 
 , 
  
 AckReplyConsumer 
  
 consumer 
 ) 
  
 - 
>  
 { 
  
 // Handle incoming message, then ack the received message. 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Id: " 
  
 + 
  
 message 
 . 
 getMessageId 
 ()); 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Data: " 
  
 + 
  
 message 
 . 
 getData 
 (). 
 toStringUtf8 
 ()); 
  
 // Print message attributes. 
  
 message 
  
 . 
 getAttributesMap 
 () 
  
 . 
 forEach 
 (( 
 key 
 , 
  
 value 
 ) 
  
 - 
>  
 System 
 . 
 out 
 . 
 println 
 ( 
 key 
  
 + 
  
 " = " 
  
 + 
  
 value 
 )); 
  
 consumer 
 . 
 ack 
 (); 
  
 }; 
  
  Subscriber 
 
  
 subscriber 
  
 = 
  
 null 
 ; 
  
 try 
  
 { 
  
 subscriber 
  
 = 
  
  Subscriber 
 
 . 
 newBuilder 
 ( 
 subscriptionName 
 , 
  
 receiver 
 ). 
 build 
 (); 
  
 // Start the subscriber. 
  
 subscriber 
 . 
  startAsync 
 
 (). 
 awaitRunning 
 (); 
  
 System 
 . 
 out 
 . 
 printf 
 ( 
 "Listening for messages on %s:\n" 
 , 
  
 subscriptionName 
 . 
  toString 
 
 ()); 
  
 // Allow the subscriber to run for 30s unless an unrecoverable error occurs. 
  
 subscriber 
 . 
 awaitTerminated 
 ( 
 30 
 , 
  
 TimeUnit 
 . 
 SECONDS 
 ); 
  
 } 
  
 catch 
  
 ( 
 TimeoutException 
  
 timeoutException 
 ) 
  
 { 
  
 // Shut down the subscriber after 30s. Stop receiving messages. 
  
 subscriber 
 . 
 stopAsync 
 (); 
  
 } 
  
 } 
 } 
 

  /** 
  
 * 
  
 TODO 
 ( 
 developer 
 ): 
  
 Uncomment 
  
 these 
  
 variables 
  
 before 
  
 running 
  
 the 
  
 sample 
 . 
  
 */ 
 // 
  
 const 
  
 subscriptionNameOrId 
  
 = 
  
 'YOUR_SUBSCRIPTION_NAME_OR_ID' 
 ; 
 // 
  
 const 
  
 timeout 
  
 = 
  
 60 
 ; 
 // 
  
 Imports 
  
 the 
  
 Google 
  
 Cloud 
  
 client 
  
 library 
 const 
  
 { 
 PubSub 
 } 
  
 = 
  
 require 
 ( 
 '@google-cloud/pubsub' 
 ); 
 // 
  
 Creates 
  
 a 
  
 client 
 ; 
  
 cache 
  
 this 
  
 for 
  
 further 
  
 use 
 const 
  
 pubSubClient 
  
 = 
  
 new 
  
 PubSub 
 (); 
 async 
  
 function 
  
 listenWithCustomAttributes 
 ( 
 subscriptionNameOrId 
 , 
  
 timeout 
 ) 
  
 { 
  
 // 
  
 References 
  
 an 
  
 existing 
  
 subscription 
 , 
  
 e 
 . 
 g 
 . 
  
 "my-subscription" 
  
 const 
  
 subscription 
  
 = 
  
 pubSubClient 
 . 
 subscription 
 ( 
 subscriptionNameOrId 
 ); 
  
 // 
  
 Create 
  
 an 
  
 event 
  
 handler 
  
 to 
  
 handle 
  
 messages 
  
 const 
  
 messageHandler 
  
 = 
  
 message 
  
 = 
>  
 { 
  
 console 
 . 
 log 
 ( 
  
 ` 
 Received 
  
 message 
 : 
  
 id 
  
 $ 
 { 
 message 
 . 
 id 
 }, 
  
 data 
  
 $ 
 { 
  
 message 
 . 
 data 
  
 }, 
  
 attributes 
 : 
  
 $ 
 { 
 JSON 
 . 
 stringify 
 ( 
 message 
 . 
 attributes 
 )} 
 ` 
 , 
  
 ); 
  
 // 
  
 "Ack" 
  
 ( 
 acknowledge 
  
 receipt 
  
 of 
 ) 
  
 the 
  
 message 
  
 message 
 . 
 ack 
 (); 
  
 }; 
  
 // 
  
 Wait 
  
 a 
  
 while 
  
 for 
  
 the 
  
 subscription 
  
 to 
  
 run 
 . 
  
 ( 
 Part 
  
 of 
  
 the 
  
 sample 
  
 only 
 . 
 ) 
  
 subscription 
 . 
 on 
 ( 
 'message' 
 , 
  
 messageHandler 
 ); 
  
 setTimeout 
 (() 
  
 = 
>  
 { 
  
 subscription 
 . 
 removeListener 
 ( 
 'message' 
 , 
  
 messageHandler 
 ); 
  
 }, 
  
 timeout 
  
 * 
  
 1000 
 ); 
 } 
 

  /** 
 * 
 TODO 
 ( 
 developer 
 ): 
 Uncomment 
 these 
 variables 
 before 
 running 
 the 
 sample 
 . 
 */ 
 // 
 const 
 subscriptionNameOrId 
 = 
 'YOUR_SUBSCRIPTION_NAME_OR_ID' 
 ; 
 // 
 const 
 timeout 
 = 
 60 
 ; 
 // 
 Imports 
 the 
 Google 
 Cloud 
 client 
 library 
 import 
  
 { 
 Message 
 , 
 PubSub 
 } 
 from 
  
 '@google-cloud/pubsub' 
 ; 
 // 
 Creates 
 a 
 client 
 ; 
 cache 
 this 
 for 
 further 
 use 
 const 
 pubSubClient 
 = 
 new 
 PubSub 
 (); 
 async 
 function 
 listenWithCustomAttributes 
 ( 
 subscriptionNameOrId 
 : 
 string 
 , 
 timeout 
 : 
 number 
 , 
 ) 
 { 
 // 
 References 
 an 
 existing 
 subscription 
 , 
 e 
 . 
 g 
 . 
 "my-subscription" 
 const 
 subscription 
 = 
 pubSubClient 
 . 
 subscription 
 ( 
 subscriptionNameOrId 
 ); 
 // 
 Create 
 an 
 event 
 handler 
 to 
 handle 
 messages 
 const 
 messageHandler 
 = 
 ( 
 message 
 : 
 Message 
 ) 
 = 
> { 
 console 
 . 
 log 
 ( 
 ` 
 Received 
 message 
 : 
 id 
 $ 
 { 
 message 
 . 
 id 
 }, 
 data 
 $ 
 { 
 message 
 . 
 data 
 }, 
 attributes 
 : 
 $ 
 { 
 JSON 
 . 
 stringify 
 ( 
 message 
 . 
 attributes 
 )} 
 ` 
 , 
 ); 
 // 
 "Ack" 
 ( 
 acknowledge 
 receipt 
 of 
 ) 
 the 
 message 
 message 
 . 
 ack 
 (); 
 }; 
 // 
 Wait 
 a 
 while 
 for 
 the 
 subscription 
 to 
 run 
 . 
 ( 
 Part 
 of 
 the 
 sample 
 only 
 . 
 ) 
 subscription 
 . 
 on 
 ( 
 'message' 
 , 
 messageHandler 
 ); 
 setTimeout 
 (() 
 = 
> { 
 subscription 
 . 
 removeListener 
 ( 
 'message' 
 , 
 messageHandler 
 ); 
 }, 
 timeout 
 * 
 1000 
 ); 
 } 
 

  from 
  
 concurrent.futures 
  
 import 
 TimeoutError 
 from 
  
 google.cloud 
  
 import 
 pubsub_v1 
 # TODO(developer) 
 # project_id = "your-project-id" 
 # subscription_id = "your-subscription-id" 
 # Number of seconds the subscriber should listen for messages 
 # timeout = 5.0 
 subscriber 
 = 
 pubsub_v1 
 . 
  SubscriberClient 
 
 () 
 subscription_path 
 = 
 subscriber 
 . 
 subscription_path 
 ( 
 project_id 
 , 
 subscription_id 
 ) 
 def 
  
 callback 
 ( 
 message 
 : 
 pubsub_v1 
 . 
 subscriber 
 . 
 message 
 . 
  Message 
 
 ) 
 - 
> None 
 : 
 print 
 ( 
 f 
 "Received 
 { 
 message 
 . 
  data 
 
 !r} 
 ." 
 ) 
 if 
 message 
 . 
  attributes 
 
 : 
 print 
 ( 
 "Attributes:" 
 ) 
 for 
 key 
 in 
 message 
 . 
  attributes 
 
 : 
 value 
 = 
 message 
 . 
  attributes 
 
 . 
 get 
 ( 
 key 
 ) 
 print 
 ( 
 f 
 " 
 { 
 key 
 } 
 : 
 { 
 value 
 } 
 " 
 ) 
 message 
 . 
  ack 
 
 () 
 streaming_pull_future 
 = 
  subscribe 
 
r . 
  subscribe 
 
 ( 
 subscription_path 
 , 
 callback 
 = 
 callback 
 ) 
 print 
 ( 
 f 
 "Listening for messages on 
 { 
 subscription_path 
 } 
 .. 
 \n 
 " 
 ) 
 # Wrap subscriber in a 'with' block to automatically call close() when done. 
 with 
 subscriber 
 : 
 try 
 : 
 # When `timeout` is not set, result() will block indefinitely, 
 # unless an exception is encountered first. 
 streaming_pull_future 
 . 
 result 
 ( 
 timeout 
 = 
 timeout 
 ) 
 except 
 TimeoutError 
 : 
 streaming_pull_future 
 . 
 cancel 
 () 
 # Trigger the shutdown. 
 streaming_pull_future 
 . 
 result 
 () 
 # Block until the shutdown is complete. 
 

  # subscription_id = "your-subscription-id" 
 pubsub 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
  PubSub 
 
 . 
  new 
 
 subscriber 
  
 = 
  
 pubsub 
 . 
  subscriber 
 
  
 subscription_id 
 listener 
  
 = 
  
 subscriber 
 . 
  listen 
 
  
 do 
  
 | 
 received_message 
 | 
  
 puts 
  
 "Received message: 
 #{ 
 received_message 
 . 
 data 
 } 
 " 
  
 unless 
  
 received_message 
 . 
 attributes 
 . 
 empty? 
  
 puts 
  
 "Attributes:" 
  
 received_message 
 . 
 attributes 
 . 
 each 
  
 do 
  
 | 
 key 
 , 
  
 value 
 | 
  
 puts 
  
 " 
 #{ 
 key 
 } 
 : 
 #{ 
 value 
 } 
 " 
  
 end 
  
 end 
  
 received_message 
 . 
  acknowledge! 
 
 end 
 listener 
 . 
  start 
 
 # Let the main thread sleep for 60 seconds so the thread for listening 
 # messages does not quit 
 sleep 
  
 60 
 listener 
 . 
 stop 
 . 
 wait!