/**
  * Returns a string array containing the default JMX domains of all available MBeanServers in this
  * JVM.
  *
  * @return a string array of JMX default domains
  */
 public static String[] getMBeanServerDomains() {
   Set<String> domains = new HashSet<String>();
   for (MBeanServer mbs : MBeanServerFactory.findMBeanServer(null)) {
     String domain = mbs.getDefaultDomain();
     if (domain == null) domain = "DefaultDomain";
     domains.add(domain);
   }
   return domains.toArray(new String[domains.size()]);
 }
  private static String[] findStandardMBeans(URL codeBase) throws Exception {
    Set<String> names;
    if (codeBase.getProtocol().equalsIgnoreCase("file") && codeBase.toString().endsWith("/"))
      names = findStandardMBeansFromDir(codeBase);
    else names = findStandardMBeansFromJar(codeBase);

    Set<String> standardMBeanNames = new TreeSet<String>();
    for (String name : names) {
      if (name.endsWith("MBean")) {
        String prefix = name.substring(0, name.length() - 5);
        if (names.contains(prefix)) standardMBeanNames.add(prefix);
      }
    }
    return standardMBeanNames.toArray(new String[0]);
  }
 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;
 }