Chapter 68. CometD Component Available as of Camel version 2.0 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. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cometd</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> 68.1. URI format cometd://host:port/channelName[?options] The channelName represents a topic that can be subscribed to by the Camel endpoints. 68.2. Examples where cometds: represents an SSL configured endpoint. 68.3. Options The CometD component supports 8 options, which are listed below. Name Description Default Type sslKeyPassword (security) The password for the keystore when using SSL. String sslPassword (security) The password when using SSL. String sslKeystore (security) The path to the keystore. String securityPolicy (security) To use a custom configured SecurityPolicy to control authorization SecurityPolicy extensions (common) To use a list of custom BayeuxServer.Extension that allows modifying incoming and outgoing requests. List sslContextParameters (security) To configure security using SSLContextParameters SSLContextParameters useGlobalSslContext Parameters (security) Enable usage of global SSL context parameters. false boolean resolveProperty Placeholders (advanced) Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true boolean The CometD endpoint is configured using URI syntax: with the following path and query parameters: 68.3.1. Path Parameters (3 parameters): Name Description Default Type host Required Hostname String port Required Host port number int channelName Required The channelName represents a topic that can be subscribed to by the Camel endpoints. String 68.3.2. Query Parameters (16 parameters): Name Description Default Type allowedOrigins (common) The origins domain that support to cross, if the crosssOriginFilterOn is true * String baseResource (common) 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 String crossOriginFilterOn (common) If true, the server will support for cross-domain filtering false boolean filterPath (common) The filterPath will be used by the CrossOriginFilter, if the crosssOriginFilterOn is true String interval (common) The client side poll timeout in milliseconds. How long a client will wait between reconnects int jsonCommented (common) 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. true boolean logLevel (common) Logging level. 0=none, 1=info, 2=debug. 1 int maxInterval (common) The max client side poll timeout in milliseconds. A client will be removed if a connection is not received in this time. 30000 int multiFrameInterval (common) The client side poll timeout, if multiple connections are detected from the same browser. 1500 int timeout (common) The server side poll timeout in milliseconds. This is how long the server will hold a reconnect request before responding. 240000 int bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean sessionHeadersEnabled (consumer) Whether to include the server session headers in the Camel message when creating a Camel Message for incoming requests. false boolean exceptionHandler (consumer) To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. ExceptionHandler exchangePattern (consumer) Sets the exchange pattern when the consumer creates an exchange. ExchangePattern disconnectLocalSession (producer) Whether to disconnect local sessions after publishing a message to its channel. Disconnecting local session is needed as they are not swept by default by CometD, and therefore you can run out of memory. false boolean synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean 68.4. Spring Boot Auto-Configuration The component supports 9 options, which are listed below. Name Description Default Type camel.component.cometd.enabled Enable cometd component true Boolean camel.component.cometd.extensions To use a list of custom BayeuxServer.Extension that allows modifying incoming and outgoing requests. List camel.component.cometd.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean camel.component.cometd.security-policy To use a custom configured SecurityPolicy to control authorization. The option is a org.cometd.bayeux.server.SecurityPolicy type. String camel.component.cometd.ssl-context-parameters To configure security using SSLContextParameters. The option is a org.apache.camel.util.jsse.SSLContextParameters type. String camel.component.cometd.ssl-key-password The password for the keystore when using SSL. String camel.component.cometd.ssl-keystore The path to the keystore. String camel.component.cometd.ssl-password The password when using SSL. String camel.component.cometd.use-global-ssl-context-parameters Enable usage of global SSL context parameters. false Boolean 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 68.5. Authentication Available as of Camel 2.8 You can configure custom SecurityPolicy and Extension's to the `CometdComponent which allows you to use authentication as documented here 68.6. Setting up SSL for Cometd Component 68.6.1. Using the JSSE Configuration Utility As of Camel 2.9, the Cometd component supports SSL/TLS configuration through the Camel JSSE Configuration Utility . This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the Cometd component. You need to configure SSL on the CometdComponent. Programmatic configuration of the component KeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); TrustManagersParameters tmp = new TrustManagersParameters(); tmp.setKeyStore(ksp); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); scp.setTrustManagers(tmp); CometdComponent commetdComponent = getContext().getComponent("cometds", CometdComponent.class); commetdComponent.setSslContextParameters(scp); Spring DSL based configuration of endpoint ... <camel:sslContextParameters id="sslContextParameters"> <camel:keyManagers keyPassword="keyPassword"> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> <camel:trustManagers> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> </camel:sslContextParameters>... <bean id="cometd" class="org.apache.camel.component.cometd.CometdComponent"> <property name="sslContextParameters" ref="sslContextParameters"/> </bean> ... <to uri="cometds://127.0.0.1:443/service/test?baseResource=file:./target/test-classes/webapp&timeout=240000&interval=0&maxInterval=30000&multiFrameInterval=1500&jsonCommented=true&logLevel=2"/>... 68.7. See Also Configuring Camel Component Endpoint Getting Started

Commands:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-cometd</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
cometd://host:port/channelName[?options]
cometd://localhost:8080/service/mychannel cometds://localhost:8443/service/mychannel
cometd:host:port/channelName
KeyStoreParameters ksp = new KeyStoreParameters(); ksp.setResource("/users/home/server/keystore.jks"); ksp.setPassword("keystorePassword"); KeyManagersParameters kmp = new KeyManagersParameters(); kmp.setKeyStore(ksp); kmp.setKeyPassword("keyPassword"); TrustManagersParameters tmp = new TrustManagersParameters(); tmp.setKeyStore(ksp); SSLContextParameters scp = new SSLContextParameters(); scp.setKeyManagers(kmp); scp.setTrustManagers(tmp); CometdComponent commetdComponent = getContext().getComponent("cometds", CometdComponent.class); commetdComponent.setSslContextParameters(scp);
<camel:sslContextParameters id="sslContextParameters"> <camel:keyManagers keyPassword="keyPassword"> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> <camel:trustManagers> <camel:keyStore resource="/users/home/server/keystore.jks" password="keystorePassword"/> </camel:keyManagers> </camel:sslContextParameters> <bean id="cometd" class="org.apache.camel.component.cometd.CometdComponent"> <property name="sslContextParameters" ref="sslContextParameters"/> </bean> <to uri="cometds://127.0.0.1:443/service/test?baseResource=file:./target/test-classes/webapp&timeout=240000&interval=0&maxInterval=30000&multiFrameInterval=1500&jsonCommented=true&logLevel=2"/>