Azure Event Hubs SDK for Java
Build real-time streaming applications using the Azure Event Hubs SDK for Java.
Installation
xml
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-messaging-eventhubs</artifactId>
<version>5.19.0</version>
</dependency>
<!-- For checkpoint store (production) -->
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-messaging-eventhubs-checkpointstore-blob</artifactId>
<version>1.20.0</version>
</dependency>
Client Creation
EventHubProducerClient
java
import com.azure.messaging.eventhubs.EventHubProducerClient;
import com.azure.messaging.eventhubs.EventHubClientBuilder;
// With connection string
EventHubProducerClient producer = new EventHubClientBuilder()
.connectionString("<connection-string>", "<event-hub-name>")
.buildProducerClient();
// Full connection string with EntityPath
EventHubProducerClient producer = new EventHubClientBuilder()
.connectionString("<connection-string-with-entity-path>")
.buildProducerClient();
With DefaultAzureCredential
java
import com.azure.identity.DefaultAzureCredentialBuilder;
EventHubProducerClient producer = new EventHubClientBuilder()
.fullyQualifiedNamespace("<namespace>.servicebus.windows.net")
.eventHubName("<event-hub-name>")
.credential(new DefaultAzureCredentialBuilder().build())
.buildProducerClient();
EventHubConsumerClient
java
import com.azure.messaging.eventhubs.EventHubConsumerClient;
EventHubConsumerClient consumer = new EventHubClientBuilder()
.connectionString("<connection-string>", "<event-hub-name>")
.consumerGroup(EventHubClientBuilder.DEFAULT_CONSUMER_GROUP_NAME)
.buildConsumerClient();
Async Clients
java
import com.azure.messaging.eventhubs.EventHubProducerAsyncClient;
import com.azure.messaging.eventhubs.EventHubConsumerAsyncClient;
EventHubProducerAsyncClient asyncProducer = new EventHubClientBuilder()
.connectionString("<connection-string>", "<event-hub-name>")
.buildAsyncProducerClient();
EventHubConsumerAsyncClient asyncConsumer = new EventHubClientBuilder()
.connectionString("<connection-string>", "<event-hub-name>")
.consumerGroup("$Default")
.buildAsyncConsumerClient();
Core Patterns
Send Single Event
java
import com.azure.messaging.eventhubs.EventData;
EventData eventData = new EventData("Hello, Event Hubs!");
producer.send(Collections.singletonList(eventData));
Send Event Batch
java
import com.azure.messaging.eventhubs.EventDataBatch;
import com.azure.messaging.eventhubs.models.CreateBatchOptions;
// Create batch
EventDataBatch batch = producer.createBatch();
// Add events (returns false if batch is full)
for (int i = 0; i < 100; i++) {
EventData event = new EventData("Event " + i);
if (!batch.tryAdd(event)) {
// Batch is full, send and create new batch
producer.send(batch);
batch = producer.createBatch();
batch.tryAdd(event);
}
}
// Send remaining events
if (batch.getCount() > 0) {
producer.send(batch);
}
Send to Specific Partition
java
CreateBatchOptions options = new CreateBatchOptions()
.setPartitionId("0");
EventDataBatch batch = producer.createBatch(options);
batch.tryAdd(new EventData("Partition 0 event"));
producer.send(batch);
Send with Partition Key
java
CreateBatchOptions options = new CreateBatchOptions()
.setPartitionKey("customer-123");
EventDataBatch batch = producer.createBatch(options);
batch.tryAdd(new EventData("Customer event"));
producer.send(batch);
Event with Properties
java
EventData event = new EventData("Order created");
event.getProperties().put("orderId", "ORD-123");
event.getProperties().put("customerId", "CUST-456");
event.getProperties().put("priority", 1);
producer.send(Collections.singletonList(event));
Receive Events (Simple)
java
import com.azure.messaging.eventhubs.models.EventPosition;
import com.azure.messaging.eventhubs.models.PartitionEvent;
// Receive from specific partition
Iterable<PartitionEvent> events = consumer.receiveFromPartition(
"0", // partitionId
10, // maxEvents
EventPosition.earliest(), // startingPosition
Duration.ofSeconds(30) // timeout
);
for (PartitionEvent partitionEvent : events) {
EventData event = partitionEvent.getData();
System.out.println("Body: " + event.getBodyAsString());
System.out.println("Sequence: " + event.getSequenceNumber());
System.out.println("Offset: " + event.getOffset());
}
EventProcessorClient (Production)
java
import com.azure.messaging.eventhubs.EventProcessorClient;
import com.azure.messaging.eventhubs.EventProcessorClientBuilder;
import com.azure.messaging.eventhubs.checkpointstore.blob.BlobCheckpointStore;
import com.azure.storage.blob.BlobContainerAsyncClient;
import com.azure.storage.blob.BlobContainerClientBuilder;
// Create checkpoint store
BlobContainerAsyncClient blobClient = new BlobContainerClientBuilder()
.connectionString("<storage-connection-string>")
.containerName("checkpoints")
.buildAsyncClient();
// Create processor
EventProcessorClient processor = new EventProcessorClientBuilder()
.connectionString("<eventhub-connection-string>", "<event-hub-name>")
.consumerGroup("$Default")
.checkpointStore(new BlobCheckpointStore(blobClient))
.processEvent(eventContext -> {
EventData event = eventContext.getEventData();
System.out.println("Processing: " + event.getBodyAsString());
// Checkpoint after processing
eventContext.updateCheckpoint();
})
.processError(errorContext -> {
System.err.println("Error: " + errorContext.getThrowable().getMessage());
System.err.println("Partition: " + errorContext.getPartitionContext().getPartitionId());
})
.buildEventProcessorClient();
// Start processing
processor.start();
// Keep running...
Thread.sleep(Duration.ofMinutes(5).toMillis());
// Stop gracefully
processor.stop();
Batch Processing
java
EventProcessorClient processor = new EventProcessorClientBuilder()
.connectionString("<connection-string>", "<event-hub-name>")
.consumerGroup("$Default")
.checkpointStore(new BlobCheckpointStore(blobClient))
.processEventBatch(eventBatchContext -> {
List<EventData> events = eventBatchContext.getEvents();
System.out.printf("Received %d events%n", events.size());
for (EventData event : events) {
// Process each event
System.out.println(event.getBodyAsString());
}
// Checkpoint after batch
eventBatchContext.updateCheckpoint();
}, 50) // maxBatchSize
.processError(errorContext -> {
System.err.println("Error: " + errorContext.getThrowable());
})
.buildEventProcessorClient();
Async Receiving
java
asyncConsumer.receiveFromPartition("0", EventPosition.latest())
.subscribe(
partitionEvent -> {
EventData event = partitionEvent.getData();
System.out.println("Received: " + event.getBodyAsString());
},
error -> System.err.println("Error: " + error),
() -> System.out.println("Complete")
);
Get Event Hub Properties
java
// Get hub info
EventHubProperties hubProps = producer.getEventHubProperties();
System.out.println("Hub: " + hubProps.getName());
System.out.println("Partitions: " + hubProps.getPartitionIds());
// Get partition info
PartitionProperties partitionProps = producer.getPartitionProperties("0");
System.out.println("Begin sequence: " + partitionProps.getBeginningSequenceNumber());
System.out.println("Last sequence: " + partitionProps.getLastEnqueuedSequenceNumber());
System.out.println("Last offset: " + partitionProps.getLastEnqueuedOffset());
Event Positions
java
// Start from beginning
EventPosition.earliest()
// Start from end (new events only)
EventPosition.latest()
// From specific offset
EventPosition.fromOffset(12345L)
// From specific sequence number
EventPosition.fromSequenceNumber(100L)
// From specific time
EventPosition.fromEnqueuedTime(Instant.now().minus(Duration.ofHours(1)))
Error Handling
java
import com.azure.messaging.eventhubs.models.ErrorContext;
.processError(errorContext -> {
Throwable error = errorContext.getThrowable();
String partitionId = errorContext.getPartitionContext().getPartitionId();
if (error instanceof AmqpException) {
AmqpException amqpError = (AmqpException) error;
if (amqpError.isTransient()) {
System.out.println("Transient error, will retry");
}
}
System.err.printf("Error on partition %s: %s%n", partitionId, error.getMessage());
})
Resource Cleanup
java
// Always close clients
try {
producer.send(batch);
} finally {
producer.close();
}
// Or use try-with-resources
try (EventHubProducerClient producer = new EventHubClientBuilder()
.connectionString(connectionString, eventHubName)
.buildProducerClient()) {
producer.send(events);
}
Environment Variables
bash
EVENT_HUBS_CONNECTION_STRING=Endpoint=sb://<namespace>.servicebus.windows.net/;SharedAccessKeyName=...
EVENT_HUBS_NAME=<event-hub-name>
STORAGE_CONNECTION_STRING=<for-checkpointing>
Best Practices
- Use EventProcessorClient: For production, provides load balancing and checkpointing
- Batch Events: Use
EventDataBatch for efficient sending - Partition Keys: Use for ordering guarantees within a partition
- Checkpointing: Checkpoint after processing to avoid reprocessing
- Error Handling: Handle transient errors with retries
- Close Clients: Always close producer/consumer when done
Trigger Phrases
- "Event Hubs Java"
- "event streaming Azure"
- "real-time data ingestion"
- "EventProcessorClient"
- "event hub producer consumer"
- "partition processing"
When to Use
This skill is applicable to execute the workflow or actions described in the overview.
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