Unable to create class for custom droplet | ATG 11.1 | Jboss 6.1 - jboss6.x

Question

I'm using ATG 11.1 and Jboss 6.1. I created a sample ATG project and wrote a custom droplet in it. used runAssembler cmd to create ear. deployment was successful but getting below error.
Am I missing anything ? can anybody please help me on this.
Command to create ear
runAssembler -server "atg_production" -jboss "C:\ProgramData\6.1.0_geppetto\core-app\deployments\core.ear" -m Production
Manifest-Version: 1.0
ATG-Config-Path: config/
ATG-Required: DafEar.Admin DPS DSS DCS DAF DAF.Deployment DAF.DeploymentAgent DAS DCS.PublishingAgent PublishingAgent REST PublishingAgent
ATG-J2EE: j2ee-apps/web-app
ATG-EAR-Module: j2ee-apps/web-app
ATG-Class-Path: classes bin
ATG-Client-Update-File: true
ATG-Client-Class-Path: lib/resources.jar lib/classes.jar
11:51:47,877 ERROR [nucleusNamespace] (RMI TCP Connection(3)-10.238.91.110) Unable to create class com.droplet.lookup.AllItemsDroplet for configuration /com/droplets/lookup/AllItemsDroplet java.lang.ClassNotFoundException: com.droplet.lookup.AllItemsDroplet from [Module "deployment.core.ear.atg_bootstrap_ejb.jar:main" from Service Module Loader]: java.lang.ClassNotFoundException: com.droplet.lookup.AllItemsDroplet from [Module "deployment.core.ear.atg_bootstrap_ejb.jar:main" from Service Module Loader]
at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:196) [jboss-modules.jar:1.2.0.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:444) [jboss-modules.jar:1.2.0.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:432) [jboss-modules.jar:1.2.0.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:374) [jboss-modules.jar:1.2.0.Final-redhat-1]
at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:119) [jboss-modules.jar:1.2.0.Final-redhat-1]
at atg.nucleus.PropertyConfiguration.loadClassUsingReplacement(PropertyConfiguration.java:504) [_DAS_slib_sclasses.jar:]
at atg.nucleus.PropertyConfiguration.createNewInstance(PropertyConfiguration.java:816) [_DAS_slib_sclasses.jar:]
at atg.nucleus.PropertyConfiguration.createNewInstance(PropertyConfiguration.java:741) [_DAS_slib_sclasses.jar:]
at atg.nucleus.NucleusNameResolver.createNewInstance(NucleusNameResolver.java:1619) [_DAS_slib_sclasses.jar:]
at atg.nucleus.MultiRootNameResolver.createFromName(MultiRootNameResolver.java:833) [_DAS_slib_sclasses.jar:]
at atg.nucleus.MultiRootNameResolver.resolveName(MultiRootNameResolver.java:477) [_DAS_slib_sclasses.jar:]
at atg.nucleus.ResolveNameHelperImpl.resolveName(ResolveNameHelperImpl.java:274) [_DAS_slib_sclasses.jar:]
at atg.nucleus.MultiRootNameResolverFactory$RequestResolveNameHelper.resolveName(MultiRootNameResolverFactory.java:832) [_DAS_slib_sclasses.jar:]
at atg.servlet.DynamoHttpServletRequest.resolveNameSingleNucleus(DynamoHttpServletRequest.java:3898) [_DAS_slib_sclasses.jar:]
at atg.servlet.DynamoHttpServletRequest.resolveName(DynamoHttpServletRequest.java:3857) [_DAS_slib_sclasses.jar:]
at atg.servlet.DynamoHttpServletRequest.resolveName(DynamoHttpServletRequest.java:3967) [_DAS_slib_sclasses.jar:]
at atg.ui.component.model.ComponentManager.setComponentActive(ComponentManager.java:658) [_DAS-UI_slib_suiclasses.jar:]
at atg.ui.component.model.ComponentAgentImpl.setComponentActive(ComponentAgentImpl.java:530) [_DAS-UI_slib_suiclasses.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_51]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_51]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_51]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_51]
at atg.security.proxy.UserSessionProxy$SessionSkeletonHandler.invoke(UserSessionProxy.java:273) [_DAS_slib_sclasses.jar:]
at atg.rmi.context.ContextualSkeletonImpl.invoke(ContextualSkeletonImpl.java:127) [_DAS_slib_sclasses.jar:]
at sun.reflect.GeneratedMethodAccessor115.invoke(Unknown Source) [:1.7.0_51]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_51]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_51]
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322) [rt.jar:1.7.0_51]
at sun.rmi.transport.Transport$1.run(Transport.java:177) [rt.jar:1.7.0_51]
at sun.rmi.transport.Transport$1.run(Transport.java:174) [rt.jar:1.7.0_51]
at java.security.AccessController.doPrivileged(Native Method) [rt.jar:1.7.0_51]
at sun.rmi.transport.Transport.serviceCall(Transport.java:173) [rt.jar:1.7.0_51]
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556) [rt.jar:1.7.0_51]
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811) [rt.jar:1.7.0_51]
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670) [rt.jar:1.7.0_51]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_51]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_51]
at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_51]