org.lsst.ccs.bus.jms

Class JMSBusMessagingLayer

java.lang.Object

org.lsst.ccs.bus.jms.JMSBusMessagingLayer

All Implemented Interfaces:

Closeable, AutoCloseable, BusMessagingLayer

public class JMSBusMessagingLayer
extends Object
implements BusMessagingLayer

Field Summary

Fields inherited from interface org.lsst.ccs.bus.BusMessagingLayer

ANONYMOUS_AGENT

Constructor Summary

Constructors

Constructor and Description
JMSBusMessagingLayer()

Method Summary

Modifier and Type	Method and Description
void	addMessageListener(String agentName, BusMessageForwarder forwarder, Bus... buses) Sets up callback configuration for a topic and subsystem.
void	close() Close the Transport Layer.
void	closeFor(String agentName, Bus... buses) close entry points for a bus for an agent.
void	register(String agentName, Bus... buses) Creates low level communication entry points for a subsystem.
void	removeMessageListener(String agentName, BusMessageForwarder forwarder, Bus... buses) Removes a message listener from the forwarder list.
<T extends BusPayload> void	sendMessage(String senderAgent, Bus<T> bus, T message, String... destinations) sends a message on a bus: note that BusMessage should have sender and destination information but it is not the role of the communication layer to parse destination information such as "subsystem1, subsystem2" or "subsystem3/module"a.
<T extends BusPayload> void	sendMessageToDestination(javax.jms.JMSContext ctxt, T message, String dest, javax.jms.JMSProducer send, Bus<T> bus)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JMSBusMessagingLayer

public JMSBusMessagingLayer()

Method Detail

close

public void close()
           throws IOException

Description copied from interface: BusMessagingLayer

Close the Transport Layer. Subsequent method calls will have no effect.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface BusMessagingLayer

Throws:

IOException

addMessageListener

public void addMessageListener(String agentName,
                               BusMessageForwarder forwarder,
                               Bus... buses)

Description copied from interface: BusMessagingLayer

Sets up callback configuration for a topic and subsystem. There could be multiple Forwarder for a given bus. All callbacks are supposed to be multithreaded

Specified by:

addMessageListener in interface BusMessagingLayer

Parameters:

agentName - if empty adds a forwarder to "anonymous" agent that receives all messages

forwarder - code that handles the incoming messages

buses - if empty the forwarder listens to all buses.

closeFor

public void closeFor(String agentName,
                     Bus... buses)

Description copied from interface: BusMessagingLayer

close entry points for a bus for an agent. calls should be idempotent.

Specified by:

closeFor in interface BusMessagingLayer

Parameters:

agentName - (if empty voids the "anonymous" agent capabilities

buses - if empty all registered buses for the agent will be closed

sendMessage

public <T extends BusPayload> void sendMessage(String senderAgent,
                                               Bus<T> bus,
                                               T message,
                                               String... destinations)
                                        throws IOException

Description copied from interface: BusMessagingLayer

sends a message on a bus: note that BusMessage should have sender and destination information but it is not the role of the communication layer to parse destination information such as "subsystem1, subsystem2" or "subsystem3/module"a.

The message will be sent to all destinations plus to all the "anonymous" agents

Specified by:

sendMessage in interface BusMessagingLayer

Parameters:

senderAgent - which agent is supposed to be the initiator of the message (anonymous agents are not supposed to send message: that may fire an exception)

destinations - could be empty (means broadcast) of a single "" or a single"*" (again means broadcast) or a list of destinations (DO NOT use things such as "*", "dest1", "dest2" : this will not work!)

Throws:

IOException - this could have a list of causes if some destinations fail. as much as possible implementers will ensure that all correct destinationa are adressed: if some fail it is not mandatory to report with a special subclass of IOexception that lists all destination that failed.

See Also:

DestinationsException

sendMessageToDestination

public <T extends BusPayload> void sendMessageToDestination(javax.jms.JMSContext ctxt,
                                                            T message,
                                                            String dest,
                                                            javax.jms.JMSProducer send,
                                                            Bus<T> bus)

removeMessageListener

public void removeMessageListener(String agentName,
                                  BusMessageForwarder forwarder,
                                  Bus... buses)

Description copied from interface: BusMessagingLayer

Removes a message listener from the forwarder list.

Specified by:

removeMessageListener in interface BusMessagingLayer

buses - if empty forwarder is removed from all buses

register

public void register(String agentName,
                     Bus... buses)
              throws IOException

Description copied from interface: BusMessagingLayer

Creates low level communication entry points for a subsystem. Abstract vision is that there is a different entry point for each bus/topic.

Specified by:

register in interface BusMessagingLayer

Parameters:

agentName - name of the sending/receiving point as will be known by transport null or empty string means that the local agent will receive all messages (whatever the destination of the message is : "anonymous agent") if an agent with same name is already locally registered for these buses nothing happens (the call is idempotent), but if another agent has the same name on the network a DuplicateBusNameException may be fired (this is an optional behaviour) but this exception is reported only to the corresponding BusMembershipListener

buses - list of buses we want to connect to, if empty connects to all buses

Throws:

IOException - if connection impossible,