public interface Channel
A Bayeux channel is the primary message routing mechanism within Bayeux: both Bayeux clients and Bayeux server use channels to group listeners that are interested in receiving messages with that channel.
This interface is the common root for both the
client side representation
of a channel and the server side
representation of a channel.
Channels are identified with strings that look like paths (e.g. "/foo/bar") called "channel id". Meta channels have channel ids starting with "/meta/" and are reserved for the operation of they Bayeux protocol. Service channels have channel ids starting with "/service/" and are channels for which publish is disabled, so that only server side listeners will receive the messages.
A channel id may also be specified with wildcards. For example "/meta/*" refers to all top level meta channels like "/meta/subscribe" or "/meta/handshake". The channel "/foo/**" is deeply wild and refers to all channels like "/foo/bar", "/foo/bar/bob" and "/foo/bar/wibble/bip". Wildcards can only be specified as last segment of a channel; therefore channel "/foo/*/bar/** is an invalid channel.
| Modifier and Type | Field and Description |
|---|---|
static java.lang.String |
META
Constant representing the meta prefix
|
static java.lang.String |
META_CONNECT
Constant representing the connect meta channel
|
static java.lang.String |
META_DISCONNECT
Constant representing the disconnect meta channel
|
static java.lang.String |
META_HANDSHAKE
Constant representing the handshake meta channel.
|
static java.lang.String |
META_SUBSCRIBE
Constant representing the subscribe meta channel
|
static java.lang.String |
META_UNSUBSCRIBE
Constant representing the unsubscribe meta channel
|
static java.lang.String |
SERVICE
Constant representing the service prefix
|
| Modifier and Type | Method and Description |
|---|---|
java.lang.Object |
getAttribute(java.lang.String name)
Retrieves the value of named channel attribute.
|
java.util.Set<java.lang.String> |
getAttributeNames() |
ChannelId |
getChannelId() |
java.lang.String |
getId() |
boolean |
isBroadcast()
A broadcasting channel is a channel that is neither a
meta channel nor a service channel. |
boolean |
isDeepWild()
Tells whether a channel contains the deep wild characters '**', for example
/foo/** |
boolean |
isMeta()
Tells whether the channel is a meta channel, that is if its
id starts with "/meta/". |
boolean |
isService()
Tells whether the channel is a service channel, that is if its
id starts with "/service/". |
boolean |
isWild()
Tells whether a channel contains the wild character '*', for example
/foo/* or if it is isDeepWild(). |
java.lang.Object |
removeAttribute(java.lang.String name)
Removes a named channel attribute.
|
void |
setAttribute(java.lang.String name,
java.lang.Object value)
Sets a named channel attribute value.
|
static final java.lang.String META
static final java.lang.String SERVICE
static final java.lang.String META_HANDSHAKE
static final java.lang.String META_CONNECT
static final java.lang.String META_SUBSCRIBE
static final java.lang.String META_UNSUBSCRIBE
static final java.lang.String META_DISCONNECT
java.lang.String getId()
boolean isMeta()
Tells whether the channel is a meta channel, that is if its
id starts with "/meta/".
boolean isService()
Tells whether the channel is a service channel, that is if its
id starts with "/service/".
boolean isBroadcast()
A broadcasting channel is a channel that is neither a
meta channel nor a service channel.
boolean isWild()
Tells whether a channel contains the wild character '*', for example
/foo/* or if it is isDeepWild().
boolean isDeepWild()
Tells whether a channel contains the deep wild characters '**', for example
/foo/**
void setAttribute(java.lang.String name,
java.lang.Object value)
Sets a named channel attribute value.
Channel attributes are convenience data that allows arbitrary application data to be associated with a channel.
name - the attribute namevalue - the attribute valuejava.lang.Object getAttribute(java.lang.String name)
Retrieves the value of named channel attribute.
name - the name of the attributejava.util.Set<java.lang.String> getAttributeNames()
java.lang.Object removeAttribute(java.lang.String name)
Removes a named channel attribute.
name - the name of the attributeCopyright © 2008–2019 The CometD Project. All rights reserved.