Object in mule's registry cannot be cast to org.mule.construct.AbstractFlowConstruct on application startup - mule

Question

I'm trying to store instance of some class in mule registry on flow application startup. Below you can see my java code and flow fragment. My problem is that sometimes application deployment fails with following error:
Caused by: java.lang.ClassCastException: com.company.test.sorter.model.Config cannot be cast to org.mule.construct.AbstractFlowConstruct
at org.mule.module.management.mbean.FlowConstructService.postRegister(FlowConstructService.java:139)
at org.mule.module.management.agent.ClassloaderSwitchingMBeanWrapper.postRegister(ClassloaderSwitchingMBeanWrapper.java:101)
You can find whole stacktrace below. I must repeat: this exception is raised only sometimes, approximately every fifth deployment of unchanged application. In most cases application runs perfectly fine. I googled for this exceptions and classes but I didn't find any solution. I am using Mule 3.2.1 (standalone). Is it a bug or am I doing something wrong?
#XmlRootElement(name = "config")
public class Config {
private String x2Regex;
private String x3Regex;
private String x2QueueName;
private String x3QueueName;
// constructors, getters and setters
}
public class Initializer implements
MuleContextNotificationListener<MuleContextNotification> {
#Override
public void onNotification(MuleContextNotification notification) {
if (notification.getAction() == MuleContextNotification.CONTEXT_STARTED) {
try {
notification.getMuleContext().getRegistry().registerObject("config", new Config());
} catch (RegistrationException e) {
// cut
}
}
}
}
<notifications>
<notification event="CONTEXT"/>
<notification-listener ref="Initializer"/>
</notifications>
<spring:beans>
<spring:bean id="Initializer" name="Initializer" class="com.company.test.sorter.Initializer" doc:name="Bean"/>
</spring:beans>
Below is fragment of mule's log with exception:
+ Failed to deploy app 'number-sorter', see below +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
org.mule.module.launcher.DeploymentException: Failed to deploy application [number-sorter]
at org.mule.module.launcher.DefaultMuleDeployer.deploy(DefaultMuleDeployer.java:68)
at org.mule.module.launcher.DeploymentService.start(DeploymentService.java:175)
at org.mule.module.launcher.MuleContainer.start(MuleContainer.java:157)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.mule.module.reboot.MuleContainerWrapper.start(MuleContainerWrapper.java:56)
at org.tanukisoftware.wrapper.WrapperManager$12.run(WrapperManager.java:2788)
Caused by: org.mule.api.MuleRuntimeException: MBeans Failed to initialise
at org.mule.module.management.agent.JmxAgent$MuleContextStartedListener.onNotification(JmxAgent.java:707)
at org.mule.module.management.agent.JmxAgent$MuleContextStartedListener.onNotification(JmxAgent.java:685)
at org.mule.context.notification.Sender.dispatch(Sender.java:40)
at org.mule.context.notification.Policy.dispatch(Policy.java:122)
at org.mule.context.notification.ServerNotificationManager.notifyListeners(ServerNotificationManager.java:244)
at org.mule.context.notification.ServerNotificationManager.fireNotification(ServerNotificationManager.java:197)
at org.mule.DefaultMuleContext.fireNotification(DefaultMuleContext.java:404)
at org.mule.DefaultMuleContext.start(DefaultMuleContext.java:226)
at org.mule.module.launcher.application.DefaultMuleApplication.start(DefaultMuleApplication.java:146)
at org.mule.module.launcher.application.ApplicationWrapper.start(ApplicationWrapper.java:107)
at org.mule.module.launcher.DefaultMuleDeployer.deploy(DefaultMuleDeployer.java:52)
... 8 more
Caused by: javax.management.RuntimeMBeanException: RuntimeException thrown in postRegister method
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.postRegisterInvoke(Unknown Source)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(Unknown Source)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(Unknown Source)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(Unknown Source)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(Unknown Source)
at org.mule.module.management.agent.JmxAgent.registerFlowConstructServices(JmxAgent.java:428)
at org.mule.module.management.agent.JmxAgent$MuleContextStartedListener.onNotification(JmxAgent.java:700)
... 18 more
Caused by: java.lang.ClassCastException: com.company.test.sorter.model.Config cannot be cast to org.mule.construct.AbstractFlowConstruct
at org.mule.module.management.mbean.FlowConstructService.postRegister(FlowConstructService.java:139)
at org.mule.module.management.agent.ClassloaderSwitchingMBeanWrapper.postRegister(ClassloaderSwitchingMBeanWrapper.java:101)
... 25 more

Answer 1

Feels like a bug: after reading the source code, I find no reasonable explanation to why Mule would try to register your custom object in JMX while mistaking it for a Flow!
As a side note, why using a notification listener and the Mule registry when you can just build your object with Spring?