com.h3c.dist.bus

Interface Bus

public interface Bus

Bus provides a publish-subscribe service where multiple applications register for receiving messages of different types that they are interested. To operate on a Bus, an application must get a handle to the Bus using BusFactory.getBus(Class). Application can then subscribe for the message types it is interested in receiving notifications on the bus using registerListener(Set, BusListener)

Application can push a message to the post(BusMessage). Applications receives messages posted from then on, onto the Bus via the registered BusListener.processBusMsg(BusMessage) for all message types it has registered. When any application pushes a message,all subscribers to that message type (including the application that pushed the message, if it has subscribed) will be notified.

Method Summary

Methods

Modifier and Type	Method and Description
void	ackMessage(long msgId, BusListener listener) Acknowledge for message received.
boolean	changeMessageOwner(BusMessage msg, BusListener listener) Take ownership of an existing BusMessage.
void	delete(long msgId) Delete a Bus message.
List<BusMessage>	getMessages(Set<Integer> msgTypes) Get the list of messages of the specified types that are currently posted on the Bus.
List<BusMessage>	getMessagesByOwner(List<BusListenerId> appNameInst, Set<Integer> msgTypes) Get the list of messages of the specified types posted by given owners on the Bus.
long	post(BusMessage msg) Push a message to the Bus
long	post(BusMessage msg, BusListener listener) Push a message to the Bus.
void	registerListener(Set<Integer> msgTypes, BusListener listener) Register listener for the message types on the Bus Notifications will be sent to the listener for messages posted to the Bus from then
void	unregisterListener(BusListener listener) Unregister listener for all message types on the Bus No notifications will be sent to the listener for any messages posted to the Bus from then on.
void	unregisterListener(Set<Integer> msgTypes, BusListener listener) Unregister listener on the Bus for the specified message types.

Method Detail

ackMessage

void ackMessage(long msgId,
              BusListener listener)
                throws ServiceNotAvailableException,
                       InterruptedException

Acknowledge for message received.

Parameters:

msgId - message ID to acknowledge

listener - Bus listener object

Throws:

InterruptedException - Operation interrupted exception

ServiceNotAvailableException - Bus service is not up

registerListener

void registerListener(Set<Integer> msgTypes,
                    BusListener listener)

Register listener for the message types on the Bus Notifications will be sent to the listener for messages posted to the Bus from then

Parameters:

msgTypes - message types

listener - Bus listener object

unregisterListener

void unregisterListener(Set<Integer> msgTypes,
                      BusListener listener)

Unregister listener on the Bus for the specified message types. No notifications will be sent to the listener for messages posted to the Bus from then on.

Parameters:

msgTypes - message types

listener - Bus listener object

unregisterListener

void unregisterListener(BusListener listener)

Unregister listener for all message types on the Bus No notifications will be sent to the listener for any messages posted to the Bus from then on.

Parameters:

listener - Bus listener object

post

long post(BusMessage msg)
          throws ServiceNotAvailableException,
                 IOException,
                 InterruptedException

Push a message to the Bus

Parameters:

msg - message to be pushed

Returns:

message id of the newly posted message

Throws:

ServiceNotAvailableException - Bus service is down

InterruptedException - Operation interrupted exception

IOException - IO Exception while data serialization

post

long post(BusMessage msg,
        BusListener listener)
          throws ServiceNotAvailableException,
                 IOException,
                 InterruptedException

Push a message to the Bus. This method will be called by an application when acknowledgment is required.

Parameters:

msg - message to be pushed

listener - Bus listener object

Returns:

message id of the newly posted message

Throws:

ServiceNotAvailableException - Bus service is down

IOException - IO Exception while data serialization

InterruptedException - Operation interrupted exception

delete

void delete(long msgId)
            throws ServiceNotAvailableException,
                   InterruptedException

Delete a Bus message. Its a NOOP if the message to be deleted is not found.

Parameters:

msgId - Bus message id to be deleted

Throws:

ServiceNotAvailableException - Bus service is down

InterruptedException - Operation interrupted exception

getMessages

List<BusMessage> getMessages(Set<Integer> msgTypes)
                             throws ServiceNotAvailableException,
                                    InterruptedException

Get the list of messages of the specified types that are currently posted on the Bus. The messages are ordered by the time of insertion onto the Bus

Parameters:

msgTypes - list of message types to be retrieved

Returns:

List of Bus message

Throws:

ServiceNotAvailableException - Bus service is down

InterruptedException - Operation interrupted exception

getMessagesByOwner

List<BusMessage> getMessagesByOwner(List<BusListenerId> appNameInst,
                                  Set<Integer> msgTypes)
                                    throws ServiceNotAvailableException,
                                           InterruptedException

Get the list of messages of the specified types posted by given owners on the Bus. The messages are ordered by the time of insertion onto the Bus

Parameters:

appNameInst - list of message owner's name and instance

msgTypes - list of message types to be retrieved

Returns:

List of Bus message

Throws:

ServiceNotAvailableException - Bus service is down

InterruptedException - Operation interrupted exception

changeMessageOwner

boolean changeMessageOwner(BusMessage msg,
                         BusListener listener)
                           throws ServiceNotAvailableException,
                                  InterruptedException

Take ownership of an existing BusMessage.

Parameters:

msg - message to change ownership

listener - listener of the new owner

Returns:

true on success, false otherwise

Throws:

ServiceNotAvailableException - Bus service is down

InterruptedException - Operation interrupted exception