So far we have seen that generic message objects are sent-to and received-from simple channel objects. Here is Spring Integration's callback interface for handling the Messages:

public interface MessageHandler {
    Message<?> handle(Message<?> message);
}

The handler plays an important role, since it is typically responsible for translating between the generic Message objects and the domain objects or primitive values expected by business components that consume the message payload. That said, developers will rarely need to implement this interface directly. While that option will always be available, we will soon discuss the higher-level configuration options including both annotation-driven techniques and XML-based configuration with convenient namespace support.