To improve compatibility between Spring's messaging classes and
Spring Integration, the type of Message that is created has been made
pluggable through the introduction of a factory abstraction;
MessageFactory.
By default a MessageFactory is provided that will create
org.springframework.messaging.GenericMessage instances, however this
can be replaced with an alternative implementation. For example,
Spring Integration can provide an implementation that creates
org.springframework.integration.message.GenericMessage instances.
This control over the type of Message that's created allows messages
to flow from Spring messaging code into Spring Integration code without
any need for conversion. In further support of this goal,
MessageChannel, MessageHandler, and SubscribableChannel have been
genericized to make the Message type that they deal with more
flexible.
org.springframework.web.stomp is now
org.springframework.web.messaging.stomp
Also classes in the ~.stomp.server and ~.stomp.adapter packages have
been renamed.
Allow WebSocketHandler methods to raise an exception.
By default we install ExceptionWebSocketHandlerDecorator, which logs
unhandled exceptions and closes the session. That decorator can be
extended or replaced.
Any exceptions that remain unhandled still (i.e. no exception handling
decorator), are caught in the lowest level before propagating to the
WebSocket engine or a SockJS transport handler and handled the same
way. That means default behavior is guaranteed but also fully
customizable.