Azure Eventgrid Java

1---
2name: azure-eventgrid-java
3description: Build event-driven applications with Azure Event Grid SDK for Java. Use when publishing events, implementing pub/sub patterns, or integrating with Azure services via events.
4package: com.azure:azure-messaging-eventgrid
5---
6 
7# Azure Event Grid SDK for Java
8 
9Build event-driven applications using the Azure Event Grid SDK for Java.
10 
11## Installation
12 
13```xml
14<dependency>
15    <groupId>com.azure</groupId>
16    <artifactId>azure-messaging-eventgrid</artifactId>
17    <version>4.27.0</version>
18</dependency>
19```
20 
21## Client Creation
22 
23### EventGridPublisherClient
24 
25```java
26import com.azure.messaging.eventgrid.EventGridPublisherClient;
27import com.azure.messaging.eventgrid.EventGridPublisherClientBuilder;
28import com.azure.core.credential.AzureKeyCredential;
29 
30// With API Key
31EventGridPublisherClient<EventGridEvent> client = new EventGridPublisherClientBuilder()
32    .endpoint("<topic-endpoint>")
33    .credential(new AzureKeyCredential("<access-key>"))
34    .buildEventGridEventPublisherClient();
35 
36// For CloudEvents
37EventGridPublisherClient<CloudEvent> cloudClient = new EventGridPublisherClientBuilder()
38    .endpoint("<topic-endpoint>")
39    .credential(new AzureKeyCredential("<access-key>"))
40    .buildCloudEventPublisherClient();
41```
42 
43### With DefaultAzureCredential
44 
45```java
46import com.azure.identity.DefaultAzureCredentialBuilder;
47 
48EventGridPublisherClient<EventGridEvent> client = new EventGridPublisherClientBuilder()
49    .endpoint("<topic-endpoint>")
50    .credential(new DefaultAzureCredentialBuilder().build())
51    .buildEventGridEventPublisherClient();
52```
53 
54### Async Client
55 
56```java
57import com.azure.messaging.eventgrid.EventGridPublisherAsyncClient;
58 
59EventGridPublisherAsyncClient<EventGridEvent> asyncClient = new EventGridPublisherClientBuilder()
60    .endpoint("<topic-endpoint>")
61    .credential(new AzureKeyCredential("<access-key>"))
62    .buildEventGridEventPublisherAsyncClient();
63```
64 
65## Event Types
66 
67| Type | Description |
68|------|-------------|
69| `EventGridEvent` | Azure Event Grid native schema |
70| `CloudEvent` | CNCF CloudEvents 1.0 specification |
71| `BinaryData` | Custom schema events |
72 
73## Core Patterns
74 
75### Publish EventGridEvent
76 
77```java
78import com.azure.messaging.eventgrid.EventGridEvent;
79import com.azure.core.util.BinaryData;
80 
81EventGridEvent event = new EventGridEvent(
82    "resource/path",           // subject
83    "MyApp.Events.OrderCreated", // eventType
84    BinaryData.fromObject(new OrderData("order-123", 99.99)), // data
85    "1.0"                      // dataVersion
86);
87 
88client.sendEvent(event);
89```
90 
91### Publish Multiple Events
92 
93```java
94List<EventGridEvent> events = Arrays.asList(
95    new EventGridEvent("orders/1", "Order.Created", 
96        BinaryData.fromObject(order1), "1.0"),
97    new EventGridEvent("orders/2", "Order.Created", 
98        BinaryData.fromObject(order2), "1.0")
99);
100 
101client.sendEvents(events);
102```
103 
104### Publish CloudEvent
105 
106```java
107import com.azure.core.models.CloudEvent;
108import com.azure.core.models.CloudEventDataFormat;
109 
110CloudEvent cloudEvent = new CloudEvent(
111    "/myapp/orders",           // source
112    "order.created",           // type
113    BinaryData.fromObject(orderData), // data
114    CloudEventDataFormat.JSON  // dataFormat
115);
116cloudEvent.setSubject("orders/12345");
117cloudEvent.setId(UUID.randomUUID().toString());
118 
119cloudClient.sendEvent(cloudEvent);
120```
121 
122### Publish CloudEvents Batch
123 
124```java
125List<CloudEvent> cloudEvents = Arrays.asList(
126    new CloudEvent("/app", "event.type1", BinaryData.fromString("data1"), CloudEventDataFormat.JSON),
127    new CloudEvent("/app", "event.type2", BinaryData.fromString("data2"), CloudEventDataFormat.JSON)
128);
129 
130cloudClient.sendEvents(cloudEvents);
131```
132 
133### Async Publishing
134 
135```java
136asyncClient.sendEvent(event)
137    .subscribe(
138        unused -> System.out.println("Event sent successfully"),
139        error -> System.err.println("Error: " + error.getMessage())
140    );
141 
142// With multiple events
143asyncClient.sendEvents(events)
144    .doOnSuccess(unused -> System.out.println("All events sent"))
145    .doOnError(error -> System.err.println("Failed: " + error))
146    .block(); // Block if needed
147```
148 
149### Custom Event Data Class
150 
151```java
152public class OrderData {
153    private String orderId;
154    private double amount;
155    private String customerId;
156    
157    public OrderData(String orderId, double amount) {
158        this.orderId = orderId;
159        this.amount = amount;
160    }
161    
162    // Getters and setters
163}
164 
165// Usage
166OrderData order = new OrderData("ORD-123", 150.00);
167EventGridEvent event = new EventGridEvent(
168    "orders/" + order.getOrderId(),
169    "MyApp.Order.Created",
170    BinaryData.fromObject(order),
171    "1.0"
172);
173```
174 
175## Receiving Events
176 
177### Parse EventGridEvent
178 
179```java
180import com.azure.messaging.eventgrid.EventGridEvent;
181 
182// From JSON string (e.g., webhook payload)
183String jsonPayload = "[{\"id\": \"...\", ...}]";
184List<EventGridEvent> events = EventGridEvent.fromString(jsonPayload);
185 
186for (EventGridEvent event : events) {
187    System.out.println("Event Type: " + event.getEventType());
188    System.out.println("Subject: " + event.getSubject());
189    System.out.println("Event Time: " + event.getEventTime());
190    
191    // Get data
192    BinaryData data = event.getData();
193    OrderData orderData = data.toObject(OrderData.class);
194}
195```
196 
197### Parse CloudEvent
198 
199```java
200import com.azure.core.models.CloudEvent;
201 
202String cloudEventJson = "[{\"specversion\": \"1.0\", ...}]";
203List<CloudEvent> cloudEvents = CloudEvent.fromString(cloudEventJson);
204 
205for (CloudEvent event : cloudEvents) {
206    System.out.println("Type: " + event.getType());
207    System.out.println("Source: " + event.getSource());
208    System.out.println("ID: " + event.getId());
209    
210    MyEventData data = event.getData().toObject(MyEventData.class);
211}
212```
213 
214### Handle System Events
215 
216```java
217import com.azure.messaging.eventgrid.systemevents.*;
218 
219for (EventGridEvent event : events) {
220    if (event.getEventType().equals("Microsoft.Storage.BlobCreated")) {
221        StorageBlobCreatedEventData blobData = 
222            event.getData().toObject(StorageBlobCreatedEventData.class);
223        System.out.println("Blob URL: " + blobData.getUrl());
224    }
225}
226```
227 
228## Event Grid Namespaces (MQTT/Pull)
229 
230### Receive from Namespace Topic
231 
232```java
233import com.azure.messaging.eventgrid.namespaces.EventGridReceiverClient;
234import com.azure.messaging.eventgrid.namespaces.EventGridReceiverClientBuilder;
235import com.azure.messaging.eventgrid.namespaces.models.*;
236 
237EventGridReceiverClient receiverClient = new EventGridReceiverClientBuilder()
238    .endpoint("<namespace-endpoint>")
239    .credential(new AzureKeyCredential("<key>"))
240    .topicName("my-topic")
241    .subscriptionName("my-subscription")
242    .buildClient();
243 
244// Receive events
245ReceiveResult result = receiverClient.receive(10, Duration.ofSeconds(30));
246 
247for (ReceiveDetails detail : result.getValue()) {
248    CloudEvent event = detail.getEvent();
249    System.out.println("Event: " + event.getType());
250    
251    // Acknowledge the event
252    receiverClient.acknowledge(Arrays.asList(detail.getBrokerProperties().getLockToken()));
253}
254```
255 
256### Reject or Release Events
257 
258```java
259// Reject (don't retry)
260receiverClient.reject(Arrays.asList(lockToken));
261 
262// Release (retry later)
263receiverClient.release(Arrays.asList(lockToken));
264 
265// Release with delay
266receiverClient.release(Arrays.asList(lockToken), 
267    new ReleaseOptions().setDelay(ReleaseDelay.BY_60_SECONDS));
268```
269 
270## Error Handling
271 
272```java
273import com.azure.core.exception.HttpResponseException;
274 
275try {
276    client.sendEvent(event);
277} catch (HttpResponseException e) {
278    System.out.println("Status: " + e.getResponse().getStatusCode());
279    System.out.println("Error: " + e.getMessage());
280}
281```
282 
283## Environment Variables
284 
285```bash
286EVENT_GRID_TOPIC_ENDPOINT=https://<topic-name>.<region>.eventgrid.azure.net/api/events
287EVENT_GRID_ACCESS_KEY=<your-access-key>
288```
289 
290## Best Practices
291 
2921. **Batch Events**: Send multiple events in one call when possible
2932. **Idempotency**: Include unique event IDs for deduplication
2943. **Schema Validation**: Use strongly-typed event data classes
2954. **Retry Logic**: Built-in, but consider dead-letter for failures
2965. **Event Size**: Keep events under 1MB (64KB for basic tier)
297 
298## Trigger Phrases
299 
300- "Event Grid Java"
301- "publish events Azure"
302- "CloudEvent SDK"
303- "event-driven messaging"
304- "pub/sub Azure"
305- "webhook events"
306