Getting started with Cometd

The Atmosphere Framework supports the Cometd/Bayeux Protocol framework. All existing applications can be deployed without any change. The big difference is you can now run your Cometd application on all supported WebServers, not only on Jetty. The WebSockets supports is also portable, e.g you can run WebSocket apps on top of Tomcat 7.0.27, which support WebSockets.

To use Cometd extension, define in your pom.xml

        <dependency>
            <groupId>org.atmosphere</groupId>
            <artifactId>atmosphere-cometd</artifactId>
            <version>...</version>
        </dependency>

Next, in your web.xml, replace the normal CometdServlet with the Atmosphere's one called org.atmosphere.cometd.CometdServlet

    <servlet>
        <servlet-name>cometd</servlet-name>
        <servlet-class>org.atmosphere.cometd.CometdServlet</servlet-class>
        <init-param>
            <param-name>timeout</param-name>
            <param-value>20000</param-value>
        </init-param>
        <init-param>
            <param-name>interval</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>maxInterval</param-name>
            <param-value>10000</param-value>
        </init-param>
        <init-param>
            <param-name>maxLazyTimeout</param-name>
            <param-value>5000</param-value>
        </init-param>
        <init-param>
            <param-name>long-polling.multiSessionInterval</param-name>
            <param-value>2000</param-value>
        </init-param>
        <init-param>
            <param-name>logLevel</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>services</param-name>
            <param-value>org.cometd.examples.ChatService</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>cometd</servlet-name>
        <url-pattern>/cometd/*</url-pattern>
    </servlet-mapping>
</web-app>

Just deploy your application and that's it.