Cometd

Page edited by charles Moulliard

Cometd Component

The cometd: component is a transport for working with the jetty implementation of the cometd/bayeux protocol.
Using this component in combination with the dojo toolkit library it's possible to push Camel messages directly into the browser using an AJAX based mechanism.

URI format

cometd://host:port/channelName[?options]

The channelName represents a topic that can be subscribed to by the Camel endpoints.

Examples

cometd://localhost:8080/service/mychannel
cometds://localhost:8443/service/mychannel

where cometds: represents an SSL configured endpoint.

See this blog entry by David Greco who contributed this component to Apache Camel, for a full sample.

Options

Name	Default Value	Description
`baseResource`		The root directory for the web resources or classpath. Use the protocol file: or classpath: depending if you want that the component loads the resource from file system or classpath. Classpath is required for OSGI deployment where the resources are packaged in the jar
`timeout`	`240000`	The server side poll timeout in milliseconds. This is how long the server will hold a reconnect request before responding.
`interval`	`0`	The client side poll timeout in milliseconds. How long a client will wait between reconnects
`maxInterval`	`30000`	The max client side poll timeout in milliseconds. A client will be removed if a connection is not received in this time.
`multiFrameInterval`	`1500`	The client side poll timeout, if multiple connections are detected from the same browser.
`jsonCommented`	`true`	If `true`, the server will accept JSON wrapped in a comment and will generate JSON wrapped in a comment. This is a defence against Ajax Hijacking.
`logLevel`	`1`	`0`=none, `1`=info, `2`=debug.

You can append query options to the URI in the following format, ?option=value&option=value&...

Here is some examples on How to pass the parameters

For file (for webapp resources located in the Web Application directory --> cometd://localhost:8080?resourceBase=file./webapp
For classpath (when by example the web resources are packaged inside the webapp folder --> cometd://localhost:8080?resourceBase=classpath:webapp