JMXConnector con=
      JMXConnectorFactory.connect(new JMXServiceURL("rmi", "host", 80, "path"));
MBeanServerConnection serverconn=con.getMBeanServerConnection();
MemoryMXBean memory=new MemoryProxy(serverconn);
MemoryUsage usage=memory.getHeapMemoryUsage();
System.out.println("Committed memory (Bytes): "+usage.getCommitted());

Example 5: Another way of using a connector to get the (remote) reference.