Package org.a2aproject.sdk.server.tasks

Class BasePushNotificationSender

java.lang.Object

org.a2aproject.sdk.server.tasks.BasePushNotificationSender

All Implemented Interfaces:

PushNotificationSender

@ApplicationScoped
public class BasePushNotificationSender
extends Object
implements PushNotificationSender

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_PAGE_SIZE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BasePushNotificationSender()	No-args constructor for CDI proxy creation.
	BasePushNotificationSender(PushNotificationConfigStore configStore)
	BasePushNotificationSender(PushNotificationConfigStore configStore, jakarta.enterprise.inject.Instance<PushNotificationPayloadFormatter> formatters)
	BasePushNotificationSender(PushNotificationConfigStore configStore, A2AHttpClient httpClient)
	BasePushNotificationSender(PushNotificationConfigStore configStore, A2AHttpClient httpClient, List<PushNotificationPayloadFormatter> formatters)

Method Summary

Modifier and Type	Method	Description
protected @Nullable String	extractTaskId(StreamingEventKind event)	Extracts the task ID from a StreamingEventKind event.
void	sendNotification(StreamingEventKind event, @Nullable Task taskSnapshot)	Sends a push notification containing a streaming event.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

See Also:

• Constant Field Values

Constructor Details

BasePushNotificationSender

protected BasePushNotificationSender()

No-args constructor for CDI proxy creation. CDI requires a non-private constructor to create proxies for @ApplicationScoped beans. All fields are initialized by the @Inject constructor during actual bean creation.

BasePushNotificationSender

public BasePushNotificationSender(PushNotificationConfigStore configStore)

BasePushNotificationSender

@Inject
public BasePushNotificationSender(PushNotificationConfigStore configStore,
 jakarta.enterprise.inject.Instance<PushNotificationPayloadFormatter> formatters)

BasePushNotificationSender

public BasePushNotificationSender(PushNotificationConfigStore configStore,
 A2AHttpClient httpClient)

BasePushNotificationSender

public BasePushNotificationSender(PushNotificationConfigStore configStore,
 A2AHttpClient httpClient,
 List<PushNotificationPayloadFormatter> formatters)

Method Details

sendNotification

public void sendNotification(StreamingEventKind event,
 @Nullable Task taskSnapshot)

Description copied from interface: PushNotificationSender

Sends a push notification containing a streaming event.

Called after the event has been persisted to TaskStore. The payload format depends on the protocol version used to register the push notification configuration.

• v1.0 (default): The event is wrapped in a StreamResponse format (per A2A spec section 4.3.3) with the appropriate oneof field set (task, message, statusUpdate, or artifactUpdate).
• v0.3: The payload is a v0.3 Task JSON object, using the provided taskSnapshot. Message events are skipped.

Retrieve push notification URLs or messaging configurations from PushNotificationConfigStore using the task ID extracted from the event.

Supported event types:

• Task
• Message
• TaskStatusUpdateEvent
• TaskArtifactUpdateEvent

Error Handling: Log errors but don't throw exceptions. Notifications are best-effort and should not fail the primary request.

Specified by:

sendNotification in interface PushNotificationSender

Parameters:

event - the streaming event to send.

taskSnapshot - the current state of the task after the event has been applied. Used by formatters for older protocol versions that require the full task state in notifications.

extractTaskId

protected @Nullable String extractTaskId(StreamingEventKind event)

Extracts the task ID from a StreamingEventKind event.

Parameters:

event - the streaming event

Returns:

the task ID, or null if not available