连接厂家corba接口报异常

EmsSession_I EmsSession = EmsSession_Ihd.value;
System.out.println(EmsSession.toString());
managerNames_THolder supportedManagerList = new managerNames_THolder();
EmsSession.getSupportedManagers(supportedManagerList);
在调用接口方法getSupportedManagers时报：
org.omg.CORBA.UNKNOWN: Server-side Exception: java.lang.NullPointerException  vmcid: 0x0  minor code: 0  completed: No
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
        at org.jacorb.orb.SystemExceptionHelper.read(SystemExceptionHelper.java:173)
        at org.jacorb.orb.ReplyReceiver.getReply(ReplyReceiver.java:326)
        at org.jacorb.orb.Delegate.invoke_internal(Delegate.java:963)
        at org.jacorb.orb.Delegate.invoke(Delegate.java:857)
        at org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.java:457)
        at org.tmforum.mtnm.emsSession._EmsSession_IStub.getSupportedManagers(_EmsSession_IStub.java:224)
        at com.bc.corba.manager.util.ConnectManager.connect(ConnectManager.java:123)
        at com.bc.corba.manager.util.ConnectManager.connectBySeverName(ConnectManager.java:242)
        at com.bc.corba.manager.util.ConnectManager.main(ConnectManager.java:260)    
请帮忙看看什么问题，谢谢