com.bea.httppubsub
Interface Channel

public interface Channel

Channel represents a pub/sub channel. A channel can have sub channels beneath it like a hierarchical structure.

Inner Class Summary

static class

Channel.ChannelPattern This enum provides constants of the three channel patterns that are described in section 2.2.1 Channel Globbing of Bayeux Protocol -- Bayeux 1.0draft1 .

Method Summary

void	addSubChannel(Channel child) Add one immediate child channel to this channel
void	destroy(Client client) Destroy this channel and all subchannels beneath it
java.util.List	getClients(Channel.ChannelPattern pattern) Return back list of clients who may interested in this channel or its children, depending on pattern parameter passed in.
java.lang.String	getName() Return the fully qualified name of this Channel.
Channel	getParentChannel() Return current channel's parent or null if current channel is root.
long	getPublishedMessageCount() Get count of messages published to the channel
java.util.List	getSubChannels() Return the list of immediate child channels for the current channel
boolean	isMetaChannel() Judge whether the channel is a meta channel.
boolean	isPersistentChannel() Judge whether the channel is a persistent channel or not.
void	publish(BayeuxMessage message, Channel.ChannelPattern pattern) Publish to this channel or its child channels with specified pattern.
void	registerListener(ChannelMessageListener listener) Register ChannelMessageListener object to this Channel.
void	removeSubChannel(Channel child) Remove sub channel from this channel.
void	subscribe(Client client) Subscribe to this channel.
void	subscribe(Client client, Channel.ChannelPattern pattern) Subscribe to this channel or its child channels with specified pattern.
void	unregisterListener(ChannelMessageListener listener) Unregister ChannnelMessageListener object from this channel
void	unsubscribe(Client client) Unsubscribe from all of this channel.
void	unsubscribe(Client client, Channel.ChannelPattern pattern) Unsubscribe from this channel.

Method Detail

getName

public java.lang.String getName()

Return the fully qualified name of this Channel. It could be something like /foo/bar/baz.

Returns:

Channel name.

getParentChannel

public Channel getParentChannel()

Return current channel's parent or null if current channel is root.

Returns:

parent channel

getSubChannels

public java.util.List getSubChannels()

Return the list of immediate child channels for the current channel

Returns:

the list of immediate child channels

addSubChannel

public void addSubChannel(Channel child)

Add one immediate child channel to this channel

Parameters:

child - child channel.

removeSubChannel

public void removeSubChannel(Channel child)

Remove sub channel from this channel.

Parameters:

child - child channel.

destroy

public void destroy(Client client)

Destroy this channel and all subchannels beneath it

Parameters:

client - Client object.

getClients

public java.util.List getClients(Channel.ChannelPattern pattern)

Return back list of clients who may interested in this channel or its children, depending on pattern parameter passed in.

Parameters:

pattern - subscribe pattern, valid values are ITSELF, IMMEDIATE_SUBCHANNELS, ALL_SUBCHANNELS

Returns:

a list of client subscribing to this channel, or this channel's immediate child channels, or this channel's child channels.

subscribe

public void subscribe(Client client)
               throws PubSubSecurityException

Subscribe to this channel.

 This method is equivalent to:
     subscribe(client, ChannelPattern.ITSELF);
 

Parameters:

client - Client object.

Throws:

PubSubSecurityException - when any security error occurs.

subscribe

public void subscribe(Client client,
                      Channel.ChannelPattern pattern)
               throws PubSubSecurityException

Subscribe to this channel or its child channels with specified pattern.

• If client is interested in current channel only (/current_channel), the passed-in pattern should be ITSELF.
• If client is interested in current channel's immediate children ( /current_channel/*), the passed-in pattern should be IMMEDIATE_SUBCHANNELS
• If client is interested in all children of current channel ( /current_channel/**), the passed-in pattern should be ALL_SUBCHANNELS

Parameters:

client - client to subscribe this channel

pattern - pattern deciding which channels beneath the current channel should be subscribed.

Throws:

PubSubSecurityException - If security permission checking failure.

unsubscribe

public void unsubscribe(Client client)

Unsubscribe from all of this channel.

 This method is equivalent to:
     unsubscribe(client, ChannelPattern.ITSELF);
     unsubscribe(client, ChannelPattern.IMMEDIATE_SUBCHANNELS);
     unsubscribe(client, ChannelPattern.ALL_SUBCHANNELS);
 

Parameters:

client - client object.

unsubscribe

public void unsubscribe(Client client,
                        Channel.ChannelPattern pattern)

Unsubscribe from this channel.

• If client is interested in current channel only (/current_channel), the passed-in pattern should be ITSELF.
• If client is interested in current channel's immediate children ( /current_channel/*), the passed-in pattern should be IMMEDIATE_SUBCHANNELS
• If client is interested in all children of current channel ( /current_channel/**), the passed-in pattern should be ALL_SUBCHANNELS

Parameters:

client - client to unsubscribe this channel

pattern - pattern deciding which channels beneath the current channel should be unsubscribed.

publish

public void publish(BayeuxMessage message,
                    Channel.ChannelPattern pattern)
             throws PubSubSecurityException

Publish to this channel or its child channels with specified pattern.

• If client wants to publish messages to the current channel only, the passed-in pattern should be ITSELF.
• If client wants to publish messages to the current channel's immediate children, the passed-in pattern should be IMMEDIATE_SUBCHANNELS
• If client wants to publish messages to all child channels of the current channel, the passed-in pattern should be ALL_SUBCHANNELS

Parameters:

message - BayeuxMessage to publish.

pattern - channel pattern to decide where to publish

Throws:

PubSubSecurityException - If no permission to publish

getPublishedMessageCount

public long getPublishedMessageCount()

Get count of messages published to the channel

Returns:

count of messages published to the channel

isMetaChannel

public boolean isMetaChannel()

Judge whether the channel is a meta channel. A meta channel is a channel whose name starts with "/meta/" or equals to "/meta".

Returns:

true or false.

isPersistentChannel

public boolean isPersistentChannel()

Judge whether the channel is a persistent channel or not.

Returns:

True of false.

registerListener

public void registerListener(ChannelMessageListener listener)

Register ChannelMessageListener object to this Channel.

Parameters:

listener - ChannelMessageListener object.

unregisterListener

public void unregisterListener(ChannelMessageListener listener)

Unregister ChannnelMessageListener object from this channel

Parameters:

listener - ChannelMessageListener object.