An ESB can coordinate synchronous or asynchronous services, and in fact can provide both synchronous and asynchronous access to the same service.

ESB能够调节同步或异步服务，事实上对于同一服务可以提供同步及异步的访问。

youdao

We would use service Interface (collaborating) if the service will also require consumers of the service to provide one or more operations, perhaps to support asynchronous communication.

如果服务同样需要服务的消费者提供一种或多种操作，例如用于支持异步通信，则应使用Service Interface (collaborating)。

youdao

This new interface allows for finer grained notifications during the asynchronous invocation of a service, but it does not provide the polling mechanism formerly found in the Callback class.

藉由这个新的接口，开发人员可以实现service异步调用过程中的细粒度通知，但它并没有提供Callback类中的轮询机制。

youdao