The (supplied) TcpConnections now emit ApplicationEvents (specifically TcpConnectionEvents) when connections are opened, closed, or an exception occurs. This allows applications to be informed of changes to TCP connections using the normal Spring ApplicationListener mechanism.

AbstractTcpConnection has been renamed TcpConnectionSupport; custom connections that are subclasses of this class, can use its methods to publish events. Similarly, AbstractTcpConnectionInterceptor has been renamed to TcpConnectionInterceptorSupport.

In addition, a new <int-ip:tcp-connection-event-channel-adapter/> is provided; by default, this adapter sends all TcpConnectionEvents to a Channel.

Further, the TCP Connection Factories, now provide a new method getOpenConnectionIds(), which returns a list of identifiers for all open connections; this allows applications, for example, to broadcast to all open connections.

Finally, the connection factories also provide a new method closeConnection(String connectionId) which allows applications to explicitly close a connection using its ID.

Further documentation for these features will follow; for now, refer to the schema documentation for information about the new adapter, and JavaDocs for it as well as the other features.

AbstractCorrelatingMessageHandler provides a new property empty-group-min-timeout to allow empty group expiry to run on a longer schedule than expiring partial groups. Empty groups will not be removed from the MessageStore until they have not been modified for at least this number of milliseconds. For more information see Section 5.4.4, “Configuring an Aggregator”.

This transformer now correctly transforms byte[] and char[] payloads to String. For more information see Section 6.1, “Transformer”.