Update transaction examples

Author: pnv1

.gitignore

@@ -8,4 +8,6 @@
 **/.idea/
 **/*.iml
 **/*.iws
-ydb-cookbook/logs/app.log
+
+# Log file
+*.log

ydb-cookbook/src/main/java/tech/ydb/examples/topic/transactions/TransactionReadAsync.java

@@ -43,7 +43,6 @@ public class TransactionReadAsync extends SimpleExample {
     private static final int MESSAGES_COUNT = 5;
 
     private final CompletableFuture<Void> messageReceivedFuture = new CompletableFuture<>();
-    private long lastSeqNo = -1;
     private TableClient tableClient;
     private AsyncReader reader;
 
@@ -80,6 +79,14 @@ protected void run(GrpcTransport transport, String pathPrefix) {
         }
     }
 
+    public static void analyzeCommitStatus(Status status) {
+        if (status.isSuccess()) {
+            logger.info("Transaction committed successfully");
+        } else {
+            logger.error("Failed to commit transaction: {}", status);
+        }
+    }
+
     private class Handler extends AbstractReadEventHandler {
         private final AtomicInteger messageCounter = new AtomicInteger(0);
 
@@ -122,13 +129,6 @@ public void onMessages(DataReceivedEvent event) {
                 } else {
                     logger.info("Message received. SeqNo={}, offset={}", message.getSeqNo(), message.getOffset());
                 }
-                if (lastSeqNo > message.getSeqNo()) {
-                    logger.error("Received a message with seqNo {}. Previously got a message with seqNo {}",
-                            message.getSeqNo(), lastSeqNo);
-                    messageReceivedFuture.complete(null);
-                } else {
-                    lastSeqNo = message.getSeqNo();
-                }
 
                 // creating session and transaction
                 Result<Session> sessionResult = tableClient.createSession(Duration.ofSeconds(10)).join();
@@ -154,7 +154,9 @@ public void onMessages(DataReceivedEvent event) {
                     return; // retry or shutdown
                 }
 
-                transaction.commit().join();
+                Status commitStatus = transaction.commit().join();
+                analyzeCommitStatus(commitStatus);
+
                 if (messageCounter.incrementAndGet() >= MESSAGES_COUNT) {
                     logger.info("{} messages committed in transaction. Finishing reading.", MESSAGES_COUNT);
                     messageReceivedFuture.complete(null);

ydb-cookbook/src/main/java/tech/ydb/examples/topic/transactions/TransactionReadSync.java

@@ -18,6 +18,7 @@
 import tech.ydb.topic.read.Message;
 import tech.ydb.topic.read.SyncReader;
 import tech.ydb.topic.settings.ReaderSettings;
+import tech.ydb.topic.settings.ReceiveSettings;
 import tech.ydb.topic.settings.TopicReadSettings;
 
 /**
@@ -63,12 +64,10 @@ protected void run(GrpcTransport transport, String pathPrefix) {
                         session.executeDataQuery("SELECT 1", TxControl.id(transaction)).join();
                         // analyzeQueryResultIfNeeded();
 
-                        // Set transaction for reader.
-                        // Further messages will be committed automatically with this transaction
-                        reader.setTransaction(transaction);
-
                         //Session session
-                        Message message = reader.receive();
+                        Message message = reader.receive(ReceiveSettings.newBuilder()
+                                .setTransaction(transaction)
+                                .build());
                         byte[] messageData;
                         try {
                             messageData = message.getData();
@@ -79,6 +78,7 @@ protected void run(GrpcTransport transport, String pathPrefix) {
                         logger.info("Message received: {}", new String(messageData, StandardCharsets.UTF_8));
 
                         transaction.commit().join();
+                        // analyze commit status
                     }
                 } catch (InterruptedException exception) {
                     logger.error("Interrupted exception while waiting for message: ", exception);