messageChannelObserver to this MessageChannel, if absent.messageFilter to this MessageChannel, if absent.messageHandler to this MessageChannel, if absent.messageTranslator to this MessageChannel, if absent.MessagingObserver to this Messaging.List containing all currently added MessagingObservers.Messaging instance.MessageChannels sendMessage(Message) method is called.true if, and only if, this Messaging has started, false otherwise.true if, and only if, this MessageChannel is active, false otherwise.Message that can be sent to a MessageChannel.MessageChannel is a channel in which you can send Messages.MessageChannel instance.MessageChannel instance.MessageChannelObserver observes changes made to a MessageChannel instance.MessageChannelObservers.Messages.MessageChannel when its sendMessage(Message) method has been called.MessageTranslator is used to translate one Message being processed by a MessageChannel instance, into a possibly different one.Messaging is an abstract base class for defining a messaging system.Messaging instance.MessagingObserver observes changes made to a Messaging instance.Messaging is started.Messaging is stopped.MessageChannel instance.MessageChannel instance.Messaging.Messaging.MessageChannelObservers from this MessageChannel.MessageFilters from this MessageChannel.MessageHandlers from this MessageChannel.MessageTranslators from this MessageChannel.messageChannelObserver from this MessageChannel, if present.messageFilter from this MessageChannel, if present.messageHandler from this MessageChannel, if present.messageTranslator from this MessageChannel, if present.MessagingObserver from this Messaging.Message.Messaging instance.Messaging.Messaging.Message that represents a potentially translated version of message.