Integrate Azure Event Grid with Java Apps

Azure Event Grid SDK for Java is a client for building event-driven applications, supporting three event schemas: EventGridEvent (Azure's native schema), CloudEvent (the CNCF CloudEvents 1.0 spec), and raw BinaryData for custom schemas. EventGridPublisherClientBuilder builds a schema-specific sync or async publisher client, authenticated with an AzureKeyCredential or DefaultAzureCredential.

Publishing an EventGridEvent sets a subject, event type, data payload, and data version, and can send one event or a batch in a single call; publishing a CloudEvent sets a source, type, data, and data format, with an explicit subject and ID, also single or batched. The async client publishes reactively, subscribing to success/error callbacks or blocking when needed. Receiving parses incoming JSON (such as a webhook payload) back into typed EventGridEvent or CloudEvent lists via fromString(), reading each event's type, subject, and time, and deserializing its data payload into a custom class; built-in system events (like Microsoft.Storage.BlobCreated) deserialize into typed system-event classes such as StorageBlobCreatedEventData. Event Grid Namespaces adds an MQTT/pull-style EventGridReceiverClient scoped to a topic and subscription name: receive() pulls a batch of events with a max count and wait duration, each carrying a lock token that must be explicitly acknowledged, rejected (don't retry), or released (retry later, optionally after a fixed delay like 60 seconds).

Use it when building event-driven pub/sub with Event Grid - publishing domain events, reacting to Azure system events via webhooks, or pulling events reliably from a namespace topic with explicit ack/reject/release semantics. Choose CloudEvent over the native EventGridEvent schema when you need interoperability with other CNCF CloudEvents-compatible systems rather than an Azure-only event shape.

Input is event data (a subject/type/payload/version for EventGridEvent, or a source/type/payload/format for CloudEvent). Output is a published event, a parsed and deserialized incoming event, or - for namespace pull receivers - a batch of events with lock tokens to settle. Install it with:

<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-messaging-eventgrid</artifactId>
    <version>4.27.0</version>
</dependency>

Its own best practices: batch multiple events into one publish call when possible, include unique event IDs for deduplication since delivery isn't exactly-once, use strongly-typed event data classes for schema validation, rely on built-in retry logic but consider dead-lettering for persistent failures, and keep events under 1MB (or 64KB on the basic tier). Errors surface as HttpResponseException with a status code and message.

It publishes and receives both Azure-native EventGridEvent and CNCF-standard CloudEvent schemas, deserializes Azure system events like Blob Storage creation notifications, and supports Event Grid Namespaces' MQTT/pull-based subscription model as an alternative to standard push delivery.

Java developers building event-driven applications on Azure Event Grid - publishing domain events, consuming Azure system-event webhooks, or reliably pulling events from a namespace topic with explicit acknowledgment.