Implements various tools for the handling of messages between local/remote devices and clients.
This package contains three classes MessageInformer,MessageListener and an interfaceMessageSelector.
The default implementation of the message selector DefaultMessageSelector is as follows:
the message selector looks for messages of a certain type or messages matching a number of properties, each with a
list of values attached.
For the message to be selected, it must be an exact match. That is, a message will be selected if and only if
it has matching values for all the given properties. All messages containing at
least one value for this property will be considered. The AllMessageSelector implementation on the
other hand
declares every incoming message to be a match. Whilst the DefaultMessageSelector acts as a filter,
AllMessageSelector
simply selects all messages.
MessageSelectors are used to create new MessageListeners. That is, they enable a listener
to register their interest in a specific
type, or group of messages. A MessageListener instance is called each time an incoming message is
received. These must be registered within a
MessageInformer instance. This enables clients to receive notifications notified about every, or a
selected type of messages sent through the framework.
The package further contains classes defining DeviceReferenceHandlers upon registration of a new device
(local or remote), creating a proxy in case of
a remove device, and ServiceReferenceHandlers, holding the service references of both local and proxy
services. Both provide initialisation, updates, removal
and probing methods.
DeviceServiceRegistry implements a Registry class through which service and device listeners can be
registered, with which Device/Service references can be obtained
from either their endpoint reference or their HelloData (data associated with a received Hello
message). An HelloData instance will contain the following information