java.lang.ClassNotFoundException: com.vmware.vise.usersession.UserSessionService

I want to use the UserSessionService class from my java service project which the UI project uses via proxy.

My budle-context.xml contains

   <bean name="TestInterfaceImpl" class="com.acme.TestInterfaceImpl">

      <constructor-arg ref="userSessionService"/>

   </bean>

and bundle-context-osgi.xml contains

<osgi:serviceid="TestInterface"ref="TestInterfaceImpl"interface="com.acme.TestInterface"/>

<osgi:referenceid="userSessionService"interface="com.vmware.vise.usersession.UserSessionService"/>

I'm getting following error

Caused by: java.lang.ClassNotFoundException: com.vmware.vise.usersession.UserSessionService

      at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:513)

      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:429)

      at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:417)

      at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)

      at org.eclipse.virgo.kernel.userregion.internal.equinox.KernelBundleClassLoader.loadClass(KernelBundleClassLoader.java:134)

I even tried adding the vsphere-client-lib.jar to server/pickup folder. Still same error.

EDIT: The top level error I'm getting is

Start failed for bundle '<my bundle name>' version '1.0.0'. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userSessionService': Initialization of bean failed; nested exception is org.springframework.beans.TypeMismatchException: Failed to convert property value of type 'java.lang.String' to required type 'java.lang.Class[]' for property 'interfaces'; nested exception is java.lang.IllegalArgumentException: Cannot find class [com.vmware.vise.usersession.UserSessionService]