Package com.sap.cds.services.outbox

Interface OutboxService

All Superinterfaces:
Service
public interface OutboxService extends Service
Defines the outbox service API. The outbox can be used to couple emitting of events on a service to the currently active transaction.

The following applies when using the outbox: - The outbox message is stored in the outbox. - If the transaction fails, the outbox message is not stored in the outbox and is never emitted. - A persisted outbox message is emitted eventually (asynchronously or synchronously, depending on the outbox implementation)

  • Field Details

  • Method Details

    • unboxed

      static <S extends Service> S unboxed(S service)
      Returns the underlying service of the outbox wrapped service. The returned service instance is the underlying outbox-independent instance executing synchronously.
      Type Parameters:
      S - the type of service
      Parameters:
      service - the service to unwrap from outbox wrapping
      Returns:
      the underlying service of the outbox wrapped service.

    • submit

      void submit(String outboxEvent, OutboxMessage message)
      Stores the given OutboxMessage under the given outbox event in the outbox.
      Parameters:
      outboxEvent - the outbox event with which the message is stored and again published by the OutboxService
      message - the OutboxMessage stored and again published by the OutboxService

    • outboxed

      <S extends Service> S outboxed(S service)
      Returns a wrapper around the given service that executes asynchronously by submitting all events to this outbox instance. The returned instance can be cached, reused and is thread-safe.

      If the passed service is already wrapped with this outbox, the passed service is returned. If the passed service is wrapped by another outbox, a new wrapper for the underlying service is returned.

      Type Parameters:
      S - the type of service
      Parameters:
      service - the service to be outboxed
      Returns:
      a wrapper around the given service that executes asynchronously by submitting all events to this outbox instance.

    • outboxed

      <A extends Service> A outboxed(Service service, Class<A> asyncInterface)
      Returns a wrapper around the given service that executes asynchronously by submitting all events to this outbox instance. The returned instance can be cached, reused and is thread-safe.

      The given service is wrapped with an asynchronous interface, matching the original interface of the service, but providing all methods with a void return type. See AsyncCqnService for an example.

      If the passed service is already wrapped with this outbox, the passed service is returned. If the passed service is wrapped by another outbox, a new wrapper for the underlying service is returned.

      Type Parameters:
      A - the type of the async interface
      Parameters:
      service - the service to be outboxed
      asyncInterface - the class of the async interface
      Returns:
      a wrapper around the given service that executes asynchronously by submitting all events to this outbox instance.