private static boolean test(String proto, MBeanServer mbs) throws Exception {
    System.out.println("Testing for proto " + proto);

    JMXConnectorServer cs;
    JMXServiceURL url = new JMXServiceURL(proto, null, 0);
    try {
      cs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);
    } catch (MalformedURLException e) {
      System.out.println("System does not recognize URL: " + url + "; ignoring");
      return true;
    }
    cs.start();
    JMXServiceURL addr = cs.getAddress();
    JMXServiceURL rmiurl = new JMXServiceURL("rmi", null, 0);
    JMXConnector client = JMXConnectorFactory.connect(addr);
    MBeanServerConnection mbsc = client.getMBeanServerConnection();
    ObjectName on = new ObjectName("x:proto=" + proto + ",ok=yes");
    mbsc.createMBean(
        RMIConnectorServer.class.getName(),
        on,
        mletName,
        new Object[] {rmiurl, null},
        new String[] {JMXServiceURL.class.getName(), Map.class.getName()});
    System.out.println("Successfully deserialized with " + proto);
    mbsc.unregisterMBean(on);

    client.close();
    cs.stop();
    return true;
  }
 private Object getAttribute(ObjectName objName, String attrName)
     throws MBeanException, InstanceNotFoundException, AttributeNotFoundException,
         ReflectionException, IOException {
   final NameValueMap values = getCachedAttributes(objName, Collections.singleton(attrName));
   Object value = values.get(attrName);
   if (value != null || values.containsKey(attrName)) {
     return value;
   }
   // Not in cache, presumably because it was omitted from the
   // getAttributes result because of an exception.  Following
   // call will probably provoke the same exception.
   return conn.getAttribute(objName, attrName);
 }
 private synchronized NameValueMap getCachedAttributes(ObjectName objName, Set<String> attrNames)
     throws InstanceNotFoundException, ReflectionException, IOException {
   NameValueMap values = cachedValues.get(objName);
   if (values != null && values.keySet().containsAll(attrNames)) {
     return values;
   }
   attrNames = new TreeSet<String>(attrNames);
   Set<String> oldNames = cachedNames.get(objName);
   if (oldNames != null) {
     attrNames.addAll(oldNames);
   }
   values = new NameValueMap();
   final AttributeList attrs =
       conn.getAttributes(objName, attrNames.toArray(new String[attrNames.size()]));
   for (Attribute attr : attrs.asList()) {
     values.put(attr.getName(), attr.getValue());
   }
   cachedValues.put(objName, values);
   cachedNames.put(objName, attrNames);
   return values;
 }