jmx客户端调用问题

JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://127.0.0.1:9999/server");
JMXConnector jmxc = JMXConnectorFactory.connect(url);
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
ObjectName mBeanName = new ObjectName("HelloAgent:name=helloWorld");
mbsc.invoke(mBeanName,"printGreeting",null,null);