Map support in addition to the current CompositeData

README.md

@@ -104,16 +104,16 @@ See `javax.management.MBeanServer.getAttribute(objectName, attribute)`.
 ```
 
 
-### MBean Composite Data attribute
+### MBean Composite Data attribute (CompositeData or Map)
 
-Use `key` to specify the key of the CompositeData. See `javax.management.openmbean.CompositeData#get(key)`.
+Use `key` to specify the key of the CompositeData or Map. See `javax.management.openmbean.CompositeData#get(key)`.
 
 ```xml
  <query objectName="java.lang:type=Memory" attribute="HeapMemoryUsage" key="used"
     resultAlias="jvm.heapMemoryUsage.used"/>
 ```
 
-* You can collect all the keys of the composite data omitting `key` in the `<query />` declaration.
+* You can collect all the keys of the composite data or map omitting `key` in the `<query />` declaration.
 * Use the [expression language](https://github.com/jmxtrans/jmxtrans-agent/wiki/Expression-Language) `#key#` (or its synonym `#compositeDataKey#`) in the `resultAlias` to use the composite data key in the metric name. Sample:
 
 ```xml

src/main/java/org/jmxtrans/agent/Query.java

@@ -219,11 +219,23 @@ private void collectAndExportAttribute(MBeanServer mbeanServer, OutputWriter out
                 } else {
                     value = compositeData.get(key);
                 }
+            } else if (attributeValue instanceof Map) {
+                Map<String, Object> mapData = (Map<String, Object>) attributeValue;
+                if (key == null) {
+                    // Get for all keys
+                    for (String key : mapData.keySet()) {
+                        value = mapData.get(key);
+                        processAttributeValue(outputWriter, objectName, attribute, key, value);
+                    }
+                    return;
+                } else {
+                    value = mapData.get(key);
+                }
             } else {
                 if (key == null) {
                     value = attributeValue;
                 } else {
-                    logger.warning("Ignore NON compositeData for specified key for '" + objectName +
+                    logger.warning("Ignore NON compositeData/Map for specified key for '" + objectName +
                             "'#" + attribute + "#" + key + ": " + attributeValue);
                     return;
                 }