private AttributeList getAttributes(ObjectName objName, String[] attrNames)
throws InstanceNotFoundException, ReflectionException, IOException {
final NameValueMap values =
getCachedAttributes(objName, new TreeSet<String>(Arrays.asList(attrNames)));
final AttributeList list = new AttributeList();
for (String attrName : attrNames) {
final Object value = values.get(attrName);
if (value != null || values.containsKey(attrName)) {
list.add(new Attribute(attrName, value));
}
}
return list;
}
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;
}