@Inject with Atmosphere and Jetty embedded

I am trying to inject Atmosphere components and factories using the javax.inject.Inject annotation in a test.

In my code I have defined an instance variable as below:

@Inject
private BroadcasterFactory broadcasterFactory;

My build.gradle declares the following dependencies:

compile 'org.jboss.resteasy:jaxrs-api:3.0.11.Final'
compile 'org.jboss.resteasy:resteasy-jackson-provider:3.0.11.Final'
compile 'org.jboss.resteasy:resteasy-multipart-provider:3.0.11.Final'

compile 'net.sf.dozer:dozer:5.5.1'
compile 'com.netiq:websockify:1.6-proactive'
compile 'org.atmosphere:atmosphere-runtime:2.3.2'
compile 'javax.inject:javax.inject:1'

runtime 'org.eclipse.jetty.websocket:websocket-server:9.2.10.v20150310'
runtime 'org.eclipse.jetty:jetty-webapp:9.2.10.v20150310'
runtime 'javax.servlet:javax.servlet-api:3.0.1'

testCompile 'org.jboss.resteasy:tjws:3.0.11.Final'
testCompile 'org.mockito:mockito-core:1.10.19'

When I run my application test in debug I can see that the instance variable broadcasterFactory is null.

My configuration for Atmosphere in web.xml is the following:

<servlet>
    <servlet-name>atmosphere</servlet-name>
    <servlet-class>org.atmosphere.cpr.AtmosphereServlet</servlet-class>

    <init-param>
        <param-name>org.atmosphere.cpr.sessionSupport</param-name>
        <param-value>true</param-value>
    </init-param>
    <init-param>
        <param-name>org.atmosphere.websocket.messageContentType</param-name>
        <param-value>application/json</param-value>
    </init-param>
    <init-param>
        <param-name>org.atmosphere.websocket.bufferSize</param-name>
        <!-- Maximum value allowed by Jetty -->
        <!-- See class org.eclipse.jetty.websocket.api.WebSocketPolicy.setInputBufferSize -->
        <param-value>32768</param-value>
    </init-param>
    <init-param>
        <param-name>org.atmosphere.websocket.maxTextMessageSize</param-name>
        <param-value>102400</param-value>
    </init-param>
    <init-param>
        <param-name>org.atmosphere.cpr.asyncSupport</param-name>
        <param-value>org.atmosphere.container.Jetty9AsyncSupportWithWebSocket</param-value>
    </init-param>
    <init-param>
        <!-- http://ift.tt/1GOYlnb -->
        <param-name>org.atmosphere.cpr.broadcasterCacheClass</param-name>
        <param-value>org.atmosphere.cache.UUIDBroadcasterCache</param-value>
    </init-param>

    <load-on-startup>0</load-on-startup>
    <async-supported>true</async-supported>
</servlet>

What do I miss? Any idea that could help to understand what is the issue is welcome.