Enables annotation support for Message Endpoints. Defines the ApplicationEventMulticaster to use for this ApplicationContext. The "task-executor" reference is optional. If not provided, an instance of ThreadPoolTaskExecutor will be created by default. Defines a Point-to-Point MessageChannel. Defines a queue for messages. If 'capacity' is specified, it will be a bounded queue. Defines a queue with priority-ordering for message reception. Defines a rendezvous queue where a sender will block until the receiver arrives or vice-versa. Defines a Publish-Subscribe channel that broadcasts messages to its subscribers. Defines a message channel. Defines a Messaging Gateway. Defines a Channel Adapter that receives from a MessageSource and sends to a MessageChannel. Defines a Channel Adapter that receives from a MessageChannel and sends to a MessageConsumer. Defines an endpoint for exposing any bean reference as a service that receives request Messages from an 'input-channel' and may send reply Messages to an 'output-channel'. The 'ref' may point to an instance that has either a single public method or a method with the @ServiceActivator annotation. Otherwise, the 'method' attribute should be provided along with 'ref'. Base type for Message Endpoint elements that accept Messages from an input-channel and also may produce reply Messages to be sent to an output-channel. Base type for Message Endpoint elements that accept Messages from an input-channel. Defines a poller. Defines an interval-based trigger. Defines an cron-based trigger. Defines a MessageSelector chain. Provides a MessageSelector reference. Defines a ThreadPoolTaskExecutor. Defines a Transformer. Defines a Filter. Defines a Router. Defines a Splitter. Defines an aggregating message endpoint. Defines a resequencing message endpoint. Defines a completion strategy. Defines a list of interceptors. Each element may be a ChannelInterceptor, ref, or inner-bean. Defines a Wire Tap Channel Interceptor.