azure-eventgrid-java

Azure Event Grid SDK for Java

Azure Event Grid SDK for Java を使用して、イベント駆動型アプリケーションを構築します。

インストール

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

クライアントの作成

EventGridPublisherClient

import com.azure.messaging.eventgrid.EventGridPublisherClient;
import com.azure.messaging.eventgrid.EventGridPublisherClientBuilder;
import com.azure.core.credential.AzureKeyCredential;

// With API Key
EventGridPublisherClient<EventGridEvent> client = new EventGridPublisherClientBuilder()
    .endpoint("<topic-endpoint>")
    .credential(new AzureKeyCredential("<access-key>"))
    .buildEventGridEventPublisherClient();

// For CloudEvents
EventGridPublisherClient<CloudEvent> cloudClient = new EventGridPublisherClientBuilder()
    .endpoint("<topic-endpoint>")
    .credential(new AzureKeyCredential("<access-key>"))
    .buildCloudEventPublisherClient();

DefaultAzureCredential を使用する場合

import com.azure.identity.DefaultAzureCredentialBuilder;

EventGridPublisherClient<EventGridEvent> client = new EventGridPublisherClientBuilder()
    .endpoint("<topic-endpoint>")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildEventGridEventPublisherClient();

非同期クライアント

import com.azure.messaging.eventgrid.EventGridPublisherAsyncClient;

EventGridPublisherAsyncClient<EventGridEvent> asyncClient = new EventGridPublisherClientBuilder()
    .endpoint("<topic-endpoint>")
    .credential(new AzureKeyCredential("<access-key>"))
    .buildEventGridEventPublisherAsyncClient();

イベントの種類

種類	説明
EventGridEvent	Azure Event Grid ネイティブスキーマ
CloudEvent	CNCF CloudEvents 1.0 仕様
BinaryData	カスタムスキーマイベント

主要なパターン

EventGridEvent を発行する

import com.azure.messaging.eventgrid.EventGridEvent;
import com.azure.core.util.BinaryData;

EventGridEvent event = new EventGridEvent(
    "resource/path",           // subject
    "MyApp.Events.OrderCreated", // eventType
    BinaryData.fromObject(new OrderData("order-123", 99.99)), // data
    "1.0"                      // dataVersion
);

client.sendEvent(event);

複数のイベントを発行する

List<EventGridEvent> events = Arrays.asList(
    new EventGridEvent("orders/1", "Order.Created", 
        BinaryData.fromObject(order1), "1.0"),
    new EventGridEvent("orders/2", "Order.Created", 
        BinaryData.fromObject(order2), "1.0")
);

client.sendEvents(events);

CloudEvent を発行する

import com.azure.core.models.CloudEvent;
import com.azure.core.models.CloudEventDataFormat;

CloudEvent cloudEvent = new CloudEvent(
    "/myapp/orders",           // source
    "order.created",           // type
    BinaryData.fromObject(orderData), // data
    CloudEventDataFormat.JSON  // dataFormat
);
cloudEvent.setSubject("orders/12345");
cloudEvent.setId(UUID.randomUUID().toString());

cloudClient.sendEvent(cloudEvent);

CloudEvents をバッチで発行する

List<CloudEvent> cloudEvents = Arrays.asList(
    new CloudEvent("/app", "event.type1", BinaryData.fromString("data1"), CloudEventDataFormat.JSON),
    new CloudEvent("/app", "event.type2", BinaryData.fromString("data2"), CloudEventDataFormat.JSON)
);

cloudClient.sendEvents(cloudEvents);

非同期発行

asyncClient.sendEvent(event)
    .subscribe(
        unused -> System.out.println("Event sent successfully"),
        error -> System.err.println("Error: " + error.getMessage())
    );

// With multiple events
asyncClient.sendEvents(events)
    .doOnSuccess(unused -> System.out.println("All events sent"))
    .doOnError(error -> System.err.println("Failed: " + error))
    .block(); // Block if needed

カスタムイベントデータクラス

public class OrderData {
    private String orderId;
    private double amount;
    private String customerId;
    
    public OrderData(String orderId, double amount) {
        this.orderId = orderId;
        this.amount = amount;
    }
    
    // Getters and setters
}

// Usage
OrderData order = new OrderData("ORD-123", 150.00);
EventGridEvent event = new EventGridEvent(
    "orders/" + order.getOrderId(),
    "MyApp.Order.Created",
    BinaryData.fromObject(order),
    "1.0"
);

イベントの受信

EventGridEvent を解析する

import com.azure.messaging.eventgrid.EventGridEvent;

// From JSON string (e.g., webhook payload)
String jsonPayload = "[{\"id\": \"...\", ...}]";
List<EventGridEvent> events = EventGridEvent.fromString(jsonPayload);

for (EventGridEvent event : events) {
    System.out.println("Event Type: " + event.getEventType());
    System.out.println("Subject: " + event.getSubject());
    System.out.println("Event Time: " + event.getEventTime());
    
    // Get data
    BinaryData data = event.getData();
    OrderData orderData = data.toObject(OrderData.class);
}

CloudEvent を解析する

import com.azure.core.models.CloudEvent;

String cloudEventJson = "[{\"specversion\": \"1.0\", ...}]";
List<CloudEvent> cloudEvents = CloudEvent.fromString(cloudEventJson);

for (CloudEvent event : cloudEvents) {
    System.out.println("Type: " + event.getType());
    System.out.println("Source: " + event.getSource());
    System.out.println("ID: " + event.getId());
    
    MyEventData data = event.getData().toObject(MyEventData.class);
}

システムイベントを処理する

import com.azure.messaging.eventgrid.systemevents.*;

for (EventGridEvent event : events) {
    if (event.getEventType().equals("Microsoft.Storage.BlobCreated")) {
        StorageBlobCreatedEventData blobData = 
            event.getData().toObject(StorageBlobCreatedEventData.class);
        System.out.println("Blob URL: " + blobData.getUrl());
    }
}

Event Grid 名前空間 (MQTT/プル)

名前空間トピックから受信する

import com.azure.messaging.eventgrid.namespaces.EventGridReceiverClient;
import com.azure.messaging.eventgrid.namespaces.EventGridReceiverClientBuilder;
import com.azure.messaging.eventgrid.namespaces.models.*;

EventGridReceiverClient receiverClient = new EventGridReceiverClientBuilder()
    .endpoint("<namespace-endpoint>")
    .credential(new AzureKeyCredential("<key>"))
    .topicName("my-topic")
    .subscriptionName("my-subscription")
    .buildClient();

// Receive events
ReceiveResult result = receiverClient.receive(10, Duration.ofSeconds(30));

for (ReceiveDetails detail : result.getValue()) {
    CloudEvent event = detail.getEvent();
    System.out.println("Event: " + event.getType());
    
    // Acknowledge the event
    receiverClient.acknowledge(Arrays.asList(detail.getBrokerProperties().getLockToken()));
}

イベントを拒否または解放する

// Reject (don't retry)
receiverClient.reject(Arrays.asList(lockToken));

// Release (retry later)
receiverClient.release(Arrays.asList(lockToken));

// Release with delay
receiverClient.release(Arrays.asList(lockToken), 
    new ReleaseOptions().setDelay(ReleaseDelay.BY_60_SECONDS));

エラー処理

import com.azure.core.exception.HttpResponseException;

try {
    client.sendEvent(event);
} catch (HttpResponseException e) {
    System.out.println("Status: " + e.getResponse().getStatusCode());
    System.out.println("Error: " + e.getMessage());
}

環境変数

EVENT_GRID_TOPIC_ENDPOINT=https://<topic-name>.<region>.eventgrid.azure.net/api/events
EVENT_GRID_ACCESS_KEY=<your-access-key>

ベストプラクティス

1. イベントのバッチ処理: 可能な場合は 1 回の呼び出しで複数のイベントを送信します
2. 冪等性: 重複排除のために一意のイベント ID を含めます
3. スキーマ検証: 厳密に型指定されたイベントデータクラスを使用します
4. 再試行ロジック: 組み込みですが、失敗時のデッドレターも検討してください
5. イベントサイズ: イベントは 1MB 未満に保ちます (Basic ティアでは 64KB)

トリガーフレーズ

• "Event Grid Java"
• "publish events Azure"
• "CloudEvent SDK"
• "event-driven messaging"
• "pub/sub Azure"
• "webhook events"

使用する場合

このスキルは、概要に記載されたワークフローまたはアクションを実行する場合に適用できます。

制限事項

• このスキルは、タスクが上記の範囲に明確に一致する場合にのみ使用してください。
• 出力を、環境固有の検証、テスト、または専門家によるレビューの代替として扱わないでください。
• 必要な入力、権限、安全境界、または成功基準が欠けている場合は、停止して確認を求めてください。