ClientSessionChannel
, ConfigurableServerChannel
, ServerChannel
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 | Description |
---|---|---|
static String |
META |
Constant representing the meta prefix
|
static String |
META_CONNECT |
Constant representing the connect meta channel
|
static String |
META_DISCONNECT |
Constant representing the disconnect meta channel
|
static String |
META_HANDSHAKE |
Constant representing the handshake meta channel.
|
static String |
META_SUBSCRIBE |
Constant representing the subscribe meta channel
|
static String |
META_UNSUBSCRIBE |
Constant representing the unsubscribe meta channel
|
static String |
SERVICE |
Constant representing the service prefix
|
Modifier and Type | Method | Description |
---|---|---|
Object |
getAttribute(String name) |
Retrieves the value of named channel attribute.
|
Set<String> |
getAttributeNames() |
|
ChannelId |
getChannelId() |
|
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() . |
Object |
removeAttribute(String name) |
Removes a named channel attribute.
|
void |
setAttribute(String name,
Object value) |
Sets a named channel attribute value.
|
static final String META
static final String SERVICE
static final String META_HANDSHAKE
static final String META_CONNECT
static final String META_SUBSCRIBE
static final String META_UNSUBSCRIBE
static final String META_DISCONNECT
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(String name, 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 valueObject getAttribute(String name)
Retrieves the value of named channel attribute.
name
- the name of the attributeCopyright © 2008–2017 The CometD Project. All rights reserved.