com.apama
Type Channel


A destination for events, either a channel name or a context identifier.

Values of the Channel type are objects that hold either a string, which is a channel name, or a context object depending on how you construct it.

The Channel type lets you send an event to a channel or context. If the Channel object contains a string, then the event is sent to the channel with that name. If the Channel object contains a context, then the event is sent to that context.

A channel can either be constructed from a string or a context, or it can be initialized to empty, which is the default value. This is equivalent to creating it from an empty context. Attempting to send an event to an empty Channel or a Channel containing an empty context will throw an exception.

The benefit of using a Channel object rather than a string or context object is that the Channel object is polymorphic. For example, by using a Channel object to represent the source of a request, you could write a service monitor so that the same code sends a response to a service request. You would not need to have code for sending responses to channels and separate code for sending responses to contexts.

You cannot send an event to a sequence of Channel objects. You cannot route a Channel object, but a routable object can have a Channel object as a member. Channel objects are parseable, comparable and acyclic.
Action summary
 booleanstatic canParse(string s)

Check if the string argument can be parsed as a channel.
 com.apama.Channelclone()

Create a deep copy of this channel.
 booleanempty()

Check if this channel contains a valid destination.
 com.apama.Channelstatic parse(string s)

Parse a string as a channel.
 stringtoString()

Convert the channel to a string.
 
Action detail

canParse

boolean static canParse(string s)
Check if the string argument can be parsed as a channel.
Parameters:
s - The string to test for parseability.
Returns:
True if the string could be parsed as a channel, false otherwise.
See Also:
com.apama.Channel#parse() - See the parse method for what is parseable.

clone

com.apama.Channel clone()
Create a deep copy of this channel.
Returns:
A deep copy of this channel.

empty

boolean empty()
Check if this channel contains a valid destination.
Returns:
True if this channel contains an empty context, false otherwise.

parse

com.apama.Channel static parse(string s)
Parse a string as a channel.

Channels are represented as "com.apama.Channel(" contents ")". The contents is either a quoted string for the channel name, or it is the string form of a context.

You cannot parse the string representation of a channel that contains a context, only channels that contain string channel names.
Parameters:
s - The string to parse.
Returns:
The channel parsed from the string.
Throws:
Throws ParseException if the string cannot be parsed as a channel or it is a channel containing a context.

toString

string toString()
Convert the channel to a string.

Channels are represented as "com.apama.Channel(" contents ")". The contents is either a quoted string for the channel name, or it is the string form of a context.
Returns:
The string form of the channel.
See Also:
context#toString() - See the toString method on context for the string form of contexts.