Channel Adapters are the components responsible for interacting with external systems or other components that are external to the messaging system. As the name implies, the interaction consists of adapting the external system or component to send-to and/or receive-from a MessageChannel. Within Spring Integration, there is a distinction between source adapters and target adapters. In the 1.0 Milestone 1 release, Spring Integration includes adapters for JMS, Files, Streams, and Spring ApplicationEvents.