Publish with error handling

  namespace 
  
 pubsub 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 pubsub 
 ; 
 using 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 future 
 ; 
 using 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 StatusOr 
 ; 
 []( 
 pubsub 
 :: 
 Publisher 
  
 publisher 
 ) 
  
 { 
  
 auto 
  
 message_id 
  
 = 
  
 publisher 
 . 
 Publish 
 ( 
  
 pubsub 
 :: 
 MessageBuilder 
 {}. 
 SetData 
 ( 
 "Hello World!" 
 ). 
 Build 
 ()); 
  
 auto 
  
 done 
  
 = 
  
 message_id 
 . 
 then 
 ([]( 
 future<StatusOr<std 
 :: 
 string 
>>  
 f 
 ) 
  
 { 
  
 auto 
  
 id 
  
 = 
  
 f 
 . 
 get 
 (); 
  
 if 
  
 ( 
 ! 
 id 
 ) 
  
 throw 
  
 std 
 :: 
 move 
 ( 
 id 
 ). 
 status 
 (); 
  
 std 
 :: 
 cout 
 << 
 "Hello World! published with id=" 
 << 
 * 
 id 
 << 
 " 
 \n 
 " 
 ; 
  
 }); 
  
 // Block until the message is published 
  
 done 
 . 
 get 
 (); 
 } 
 

  using 
  
  Google.Cloud.PubSub.V1 
 
 ; 
 using 
  
 System 
 ; 
 using 
  
 System.Collections.Generic 
 ; 
 using 
  
 System.Linq 
 ; 
 using 
  
 System.Threading 
 ; 
 using 
  
 System.Threading.Tasks 
 ; 
 public 
  
 class 
  
 PublishMessagesAsyncSample 
 { 
  
 public 
  
 async 
  
 Task<int> 
  
 PublishMessagesAsync 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 topicId 
 , 
  
 IEnumerable<string> 
  
 messageTexts 
 ) 
  
 { 
  
  TopicName 
 
  
 topicName 
  
 = 
  
  TopicName 
 
 . 
  FromProjectTopic 
 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  PublisherClient 
 
  
 publisher 
  
 = 
  
 await 
  
  PublisherClient 
 
 . 
  CreateAsync 
 
 ( 
 topicName 
 ); 
  
 int 
  
 publishedMessageCount 
  
 = 
  
 0 
 ; 
  
 var 
  
 publishTasks 
  
 = 
  
 messageTexts 
 . 
 Select 
 ( 
 async 
  
 text 
  
 = 
>  
 { 
  
 try 
  
 { 
  
 string 
  
 message 
  
 = 
  
 await 
  
 publisher 
 . 
 PublishAsync 
 ( 
 text 
 ); 
  
 Console 
 . 
 WriteLine 
 ( 
 $"Published message {message}" 
 ); 
  
 Interlocked 
 . 
 Increment 
 ( 
 ref 
  
 publishedMessageCount 
 ); 
  
 } 
  
 catch 
  
 ( 
 Exception 
  
 exception 
 ) 
  
 { 
  
 Console 
 . 
 WriteLine 
 ( 
 $"An error occurred when publishing message {text}: {exception.Message}" 
 ); 
  
 } 
  
 }); 
  
 await 
  
 Task 
 . 
 WhenAll 
 ( 
 publishTasks 
 ); 
  
 // PublisherClient instance should be shutdown after use. 
  
 // The TimeSpan specifies for how long to attempt to publish locally queued messages. 
  
 await 
  
 publisher 
 . 
  ShutdownAsync 
 
 ( 
 TimeSpan 
 . 
 FromSeconds 
 ( 
 15 
 )); 
  
 return 
  
 publishedMessageCount 
 ; 
  
 } 
 } 
 

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "strconv" 
  
 "sync" 
  
 "sync/atomic" 
  
 "cloud.google.com/go/pubsub/v2" 
 ) 
 func 
  
 publishThatScales 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 projectID 
 , 
  
 topicID 
  
 string 
 , 
  
 n 
  
 int 
 ) 
  
 error 
  
 { 
  
 // projectID := "my-project-id" 
  
 // topicID := "my-topic" 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 pubsub 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 projectID 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "pubsub.NewClient: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 var 
  
 wg 
  
 sync 
 . 
 WaitGroup 
  
 var 
  
 totalErrors 
  
 uint64 
  
 // client.Publisher can be passed a topic ID (e.g. "my-topic") or 
  
 // a fully qualified name (e.g. "projects/my-project/topics/my-topic"). 
  
 // If a topic ID is provided, the project ID from the client is used. 
  
 // Reuse this publisher for all publish calls to send messages in batches. 
  
 publisher 
  
 := 
  
 client 
 . 
 Publisher 
 ( 
 topicID 
 ) 
  
 for 
  
 i 
  
 := 
  
 0 
 ; 
  
 i 
 < 
 n 
 ; 
  
 i 
 ++ 
  
 { 
  
 result 
  
 := 
  
 publisher 
 . 
 Publish 
 ( 
 ctx 
 , 
  
& pubsub 
 . 
 Message 
 { 
  
 Data 
 : 
  
 [] 
 byte 
 ( 
 "Message " 
  
 + 
  
 strconv 
 . 
 Itoa 
 ( 
 i 
 )), 
  
 }) 
  
 wg 
 . 
 Add 
 ( 
 1 
 ) 
  
 go 
  
 func 
 ( 
 i 
  
 int 
 , 
  
 res 
  
 * 
 pubsub 
 . 
 PublishResult 
 ) 
  
 { 
  
 defer 
  
 wg 
 . 
 Done 
 () 
  
 // The Get method blocks until a server-generated ID or 
  
 // an error is returned for the published message. 
  
 id 
 , 
  
 err 
  
 := 
  
 res 
 . 
 Get 
 ( 
 ctx 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 // Error handling code can be added here. 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "Failed to publish: %v" 
 , 
  
 err 
 ) 
  
 atomic 
 . 
 AddUint64 
 ( 
& totalErrors 
 , 
  
 1 
 ) 
  
 return 
  
 } 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "Published message %d; msg ID: %v\n" 
 , 
  
 i 
 , 
  
 id 
 ) 
  
 }( 
 i 
 , 
  
 result 
 ) 
  
 } 
  
 wg 
 . 
 Wait 
 () 
  
 if 
  
 totalErrors 
 > 
 0 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "%d of %d messages did not publish successfully" 
 , 
  
 totalErrors 
 , 
  
 n 
 ) 
  
 } 
  
 return 
  
 nil 
 } 
 

  import 
  
 com.google.api.core. ApiFuture 
 
 ; 
 import 
  
 com.google.api.core. ApiFutureCallback 
 
 ; 
 import 
  
 com.google.api.core. ApiFutures 
 
 ; 
 import 
  
 com.google.api.gax.rpc. ApiException 
 
 ; 
 import 
  
 com.google.cloud.pubsub.v1. Publisher 
 
 ; 
 import 
  
 com.google.common.util.concurrent.MoreExecutors 
 ; 
 import 
  
 com.google.protobuf. ByteString 
 
 ; 
 import 
  
 com.google.pubsub.v1. PubsubMessage 
 
 ; 
 import 
  
 com.google.pubsub.v1. TopicName 
 
 ; 
 import 
  
 java.io.IOException 
 ; 
 import 
  
 java.util.Arrays 
 ; 
 import 
  
 java.util.List 
 ; 
 import 
  
 java.util.concurrent.TimeUnit 
 ; 
 public 
  
 class 
 PublishWithErrorHandlerExample 
  
 { 
  
 public 
  
 static 
  
 void 
  
 main 
 ( 
 String 
 ... 
  
 args 
 ) 
  
 throws 
  
 Exception 
  
 { 
  
 // TODO(developer): Replace these variables before running the sample. 
  
 String 
  
 projectId 
  
 = 
  
 "your-project-id" 
 ; 
  
 String 
  
 topicId 
  
 = 
  
 "your-topic-id" 
 ; 
  
 publishWithErrorHandlerExample 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
 } 
  
 public 
  
 static 
  
 void 
  
 publishWithErrorHandlerExample 
 ( 
 String 
  
 projectId 
 , 
  
 String 
  
 topicId 
 ) 
  
 throws 
  
 IOException 
 , 
  
 InterruptedException 
  
 { 
  
  TopicName 
 
  
 topicName 
  
 = 
  
  TopicName 
 
 . 
 of 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  Publisher 
 
  
 publisher 
  
 = 
  
 null 
 ; 
  
 try 
  
 { 
  
 // Create a publisher instance with default settings bound to the topic 
  
 publisher 
  
 = 
  
  Publisher 
 
 . 
 newBuilder 
 ( 
 topicName 
 ). 
 build 
 (); 
  
 List<String> 
  
 messages 
  
 = 
  
 Arrays 
 . 
 asList 
 ( 
 "first message" 
 , 
  
 "second message" 
 ); 
  
 for 
  
 ( 
 final 
  
 String 
  
 message 
  
 : 
  
 messages 
 ) 
  
 { 
  
  ByteString 
 
  
 data 
  
 = 
  
  ByteString 
 
 . 
  copyFromUtf8 
 
 ( 
 message 
 ); 
  
  PubsubMessage 
 
  
 pubsubMessage 
  
 = 
  
  PubsubMessage 
 
 . 
 newBuilder 
 (). 
  setData 
 
 ( 
 data 
 ). 
 build 
 (); 
  
 // Once published, returns a server-assigned message id (unique within the topic) 
  
 ApiFuture<String> 
  
 future 
  
 = 
  
  publish 
 
er . 
  publish 
 
 ( 
 pubsubMessage 
 ); 
  
 // Add an asynchronous callback to handle success / failure 
  
  ApiFutures 
 
 . 
  addCallback 
 
 ( 
  
 future 
 , 
  
 new 
  
 ApiFutureCallback<String> 
 () 
  
 { 
  
 @Override 
  
 public 
  
 void 
  
 onFailure 
 ( 
 Throwable 
  
 throwable 
 ) 
  
 { 
  
 if 
  
 ( 
 throwable 
  
 instanceof 
  
  ApiException 
 
 ) 
  
 { 
  
  ApiException 
 
  
 apiException 
  
 = 
  
 (( 
  ApiException 
 
 ) 
  
 throwable 
 ); 
  
 // details on the API exception 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 apiException 
 . 
  getStatusCode 
 
 (). 
 getCode 
 ()); 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 apiException 
 . 
  isRetryable 
 
 ()); 
  
 } 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Error publishing message : " 
  
 + 
  
 message 
 ); 
  
 } 
  
 @Override 
  
 public 
  
 void 
  
 onSuccess 
 ( 
 String 
  
 messageId 
 ) 
  
 { 
  
 // Once published, returns server-assigned message ids (unique within the topic) 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Published message ID: " 
  
 + 
  
 messageId 
 ); 
  
 } 
  
 }, 
  
 MoreExecutors 
 . 
 directExecutor 
 ()); 
  
 } 
  
 } 
  
 finally 
  
 { 
  
 if 
  
 ( 
 publisher 
  
 != 
  
 null 
 ) 
  
 { 
  
 // When finished with the publisher, shutdown to free up resources. 
  
 publisher 
 . 
  shutdown 
 
 (); 
  
 publisher 
 . 
  awaitTermination 
 
 ( 
 1 
 , 
  
 TimeUnit 
 . 
 MINUTES 
 ); 
  
 } 
  
 } 
  
 } 
 } 
 

  # topic_id = "your-topic-id" 
 pubsub 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
  PubSub 
 
 . 
  new 
 
 publisher 
  
 = 
  
 pubsub 
 . 
  publisher 
 
  
 topic_id 
 begin 
  
 publisher 
 . 
  publish_async 
 
  
 "This is a test message." 
  
 do 
  
 | 
 result 
 | 
  
 raise 
  
 "Failed to publish the message." 
  
 unless 
  
 result 
 . 
 succeeded? 
  
 puts 
  
 "Message published asynchronously." 
  
 end 
  
 # Stop the async_publisher to send all queued messages immediately. 
  
 publisher 
 . 
  async_publisher 
 
 . 
 stop 
 . 
 wait! 
 rescue 
  
 StandardError 
  
 = 
>  
 e 
  
 puts 
  
 "Received error while publishing: 
 #{ 
 e 
 . 
 message 
 } 
 " 
 end