/** Constructs a PrintGCStat object to monitor a remote JVM. */ public PrintGCStat(MBeanServerConnection server) throws IOException { // Create the platform mxbean proxies this.rmbean = newPlatformMXBeanProxy(server, RUNTIME_MXBEAN_NAME, RuntimeMXBean.class); this.mmbean = newPlatformMXBeanProxy(server, MEMORY_MXBEAN_NAME, MemoryMXBean.class); ObjectName poolName = null; ObjectName gcName = null; try { poolName = new ObjectName(MEMORY_POOL_MXBEAN_DOMAIN_TYPE + ",*"); gcName = new ObjectName(GARBAGE_COLLECTOR_MXBEAN_DOMAIN_TYPE + ",*"); } catch (MalformedObjectNameException e) { // should not reach here assert (false); } Set<ObjectName> mbeans = server.queryNames(poolName, null); if (mbeans != null) { pools = new ArrayList<MemoryPoolMXBean>(); for (ObjectName objName : mbeans) { MemoryPoolMXBean p = newPlatformMXBeanProxy(server, objName.getCanonicalName(), MemoryPoolMXBean.class); pools.add(p); } } mbeans = server.queryNames(gcName, null); if (mbeans != null) { gcmbeans = new ArrayList<GarbageCollectorMXBean>(); for (ObjectName objName : mbeans) { GarbageCollectorMXBean gc = newPlatformMXBeanProxy( server, objName.getCanonicalName(), GarbageCollectorMXBean.class); gcmbeans.add(gc); } } }
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; }