org.avineas.fins

Interface Unit

public interface Unit

Interface definition that a FINS unit must implement to receive and communicate FINS commands. Unit implementations are wired to a gateway, which must be done via dependency injection or manual construction. Additionally, in OSGi environments, it is sufficient to register the unit as service implementing this interface: it will be automatically picked-up by the default gateway object constructed in those environments.

Since:

6-11-2005

Author:

Arie van Wijngaarden

Method Summary

Methods

Modifier and Type	Method and Description
Response	handleCommand(Command command) Handle a packet/command received from another FINS unit.
void	setTransmitter(Transmitter transmitter) Set the transmitter to use for sending commands to other FINS units.

Method Detail

handleCommand

Response handleCommand(Command command)
                       throws java.lang.Exception

Handle a packet/command received from another FINS unit. It should process it and construct a response and return it. Note that this method may be called at any time and in a multi-threaded way. The method should be aware that it is possible that, given the used network protocol, a command may be delivered multiple times, even if a correct response was passed back (the response may be lost in transit).

Parameters:

command - The command that is issued from the remote node

Returns:

The response as constructed

Throws:

java.lang.Exception - In case of severe errors, the method may throw an exception. In that case the gateway does not send a reply to the unit expecting it

setTransmitter

void setTransmitter(Transmitter transmitter)

Set the transmitter to use for sending commands to other FINS units. The method is called during construction/initialization of the gateway it is connected to to set the transmitter that can be used to send messages to another unit. The method is called both to set the transmitter and to reset the transmitter: a null value is passed to reset the transmitter, making this unit basically an orphan that needs to be wired or picked-up by another gateway.

Parameters:

transmitter - The transmitter to use for sending messages. The transmitter passed may be null. In case of a null transmitter, any previously set not-null transmitter must not be used anymore for communication since it is destroyed