azure-eventhub-java

Author's original introduction

Build real-time streaming applications with Azure Event Hubs SDK for Java. Use when implementing event streaming, high-throughput data ingestion, or building event-driven architectures.

SkillPi interpretation

Tasks

azure-eventhub-java

Audience

Use the scope in the original author introduction.

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This azure-eventhub-java package contains Microsoft Azure SDK documentation and examples, not a runtime-verified installer. Check SDK names/versions, tenant/subscription and actual endpoints; grant only task-specific least privilege. Never put administrator credentials or real secrets in samples, logs or commits. Connected cloud services may receive selected text, documents, audio, messages, logs or other input and incur charges; confirm scope, redaction and costs first. Ask the user to confirm each resource creation/update/deletion, key/access change or outbound message and test with disposable resources before production. Replace and verify placeholder endpoints and samples. SkillPi checked pinned source, complete attachments and static/antivirus evidence only; it did not run the SDK, verify service compatibility or authorize cloud access.

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caution · Static evidence review; not a runtime safety guarantee.

This azure-eventhub-java package contains Microsoft Azure SDK documentation and examples, not a runtime-verified installer. Check SDK names/versions, tenant/subscription and actual endpoints; grant only task-specific least privilege. Never put administrator credentials or real secrets in samples, logs or commits. Connected cloud services may receive selected text, documents, audio, messages, logs or other input and incur charges; confirm scope, redaction and costs first. Ask the user to confirm each resource creation/update/deletion, key/access change or outbound message and test with disposable resources before production. Replace and verify placeholder endpoints and samples. SkillPi checked pinned source, complete attachments and static/antivirus evidence only; it did not run the SDK, verify service compatibility or authorize cloud access.

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Original SKILL.md

---
name: azure-eventhub-java
description: Build real-time streaming applications with Azure Event Hubs SDK for Java. Use when implementing event streaming, high-throughput data ingestion, or building event-driven architectures.
license: MIT
metadata:
  author: Microsoft
  version: "1.0.0"
  package: com.azure:azure-messaging-eventhubs
---

# 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.core.credential.TokenCredential;
import com.azure.identity.AzureIdentityEnvVars;
import com.azure.identity.DefaultAzureCredentialBuilder;
import com.azure.identity.ManagedIdentityCredentialBuilder;

// Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>
TokenCredential credential = new DefaultAzureCredentialBuilder()
    .requireEnvVars(AzureIdentityEnvVars.AZURE_TOKEN_CREDENTIALS)
    .build();
// Or use a specific credential directly in production:
// See https://learn.microsoft.com/java/api/overview/azure/identity-readme?view=azure-java-stable#credential-classes
// TokenCredential credential = new ManagedIdentityCredentialBuilder().build();

EventHubProducerClient producer = new EventHubClientBuilder()
    .fullyQualifiedNamespace("<namespace>.servicebus.windows.net")
    .eventHubName("<event-hub-name>")
    .credential(credential)
    .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=...  # Alternative to Entra ID auth
EVENT_HUBS_NAME=<event-hub-name>  # Required for event hub name
STORAGE_CONNECTION_STRING=<for-checkpointing>  # Alternative to Entra ID auth for checkpointing
AZURE_TOKEN_CREDENTIALS=prod  # Required only if DefaultAzureCredential is used in production
```

## Best Practices

1. **Use EventProcessorClient**: For production, provides load balancing and checkpointing
2. **Batch Events**: Use `EventDataBatch` for efficient sending
3. **Partition Keys**: Use for ordering guarantees within a partition
4. **Checkpointing**: Checkpoint after processing to avoid reprocessing
5. **Error Handling**: Handle transient errors with retries
6. **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"

Copyright and license notice

    MIT License

    Copyright (c) Microsoft Corporation.

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE