Java tutorial
/******************************************************************************* * Cloud Foundry * Copyright (c) [2009-2017] Pivotal Software, Inc. All Rights Reserved. * <p/> * This product is licensed to you under the Apache License, Version 2.0 (the "License"). * You may not use this product except in compliance with the License. * <p/> * This product includes a number of subcomponents with * separate copyright notices and license terms. Your use of these * subcomponents is subject to the terms and conditions of the * subcomponent's license, as noted in the LICENSE file. *******************************************************************************/ package org.cloudfoundry.identity.statsd; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import sun.management.LazyCompositeData; import javax.management.MBeanAttributeInfo; import javax.management.MBeanInfo; import javax.management.MBeanOperationInfo; import javax.management.MBeanServerConnection; import javax.management.ObjectName; import javax.management.openmbean.CompositeDataSupport; import javax.management.openmbean.TabularDataSupport; import java.util.AbstractMap; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; @SuppressWarnings("restriction") public class MBeanMap extends AbstractMap<String, Object> { private static Log logger = LogFactory.getLog(MBeanMap.class); private Map<String, Object> map = new HashMap<String, Object>(); private boolean initialized = false; private final MBeanInfo info; private final MBeanServerConnection server; private final ObjectName name; public MBeanMap() { this(null, null); } public MBeanMap(MBeanServerConnection server, ObjectName name) { this.server = server; this.name = name; if (server != null) { try { info = server.getMBeanInfo(name); } catch (Exception e) { throw new IllegalStateException(e); } } else { info = null; } } @Override public Object put(String key, Object value) { return map.put(key, value); } @Override public Set<java.util.Map.Entry<String, Object>> entrySet() { if (!initialized && info != null) { MBeanAttributeInfo[] attributes = info.getAttributes(); for (MBeanAttributeInfo attribute : attributes) { String key = attribute.getName(); try { Object value = server.getAttribute(name, key); verySafePut(map, key, value); } catch (Exception e) { logger.trace("Cannot extract attribute: " + key); } } MBeanOperationInfo[] operations = info.getOperations(); for (MBeanOperationInfo operation : operations) { String key = operation.getName(); if (key.startsWith("get") && operation.getSignature().length == 0) { String attribute = StringUtils.camelToUnderscore(key.substring(3)); if (map.containsKey(attribute)) { continue; } try { Object value = server.invoke(name, key, null, null); verySafePut(map, attribute, value); } catch (Exception e) { logger.trace("Cannot extract operation: " + key); } } } } return map.entrySet(); } private Object getCompositeWrapper(Object value) { return getCompositeWrapper(value, true); } private Object getCompositeWrapper(Object value, boolean prettifyKeys) { if (value instanceof CompositeDataSupport) { Map<Object, Object> map = new HashMap<Object, Object>(); CompositeDataSupport composite = (CompositeDataSupport) value; for (String key : composite.getCompositeType().keySet()) { safePut(map, key, composite.get(key)); } return map; } if (value instanceof LazyCompositeData) { Map<Object, Object> map = new HashMap<Object, Object>(); LazyCompositeData composite = (LazyCompositeData) value; for (String key : composite.getCompositeType().keySet()) { safePut(map, key, composite.get(key)); } return map; } if (value instanceof TabularDataSupport) { Map<Object, Object> map = new HashMap<Object, Object>(); TabularDataSupport composite = (TabularDataSupport) value; for (Entry<Object, Object> entry : composite.entrySet()) { Object wrapper = getCompositeWrapper(entry.getValue()); if (isKeyValuePair(wrapper)) { String key = getKey(wrapper); safePut(map, key, getValue(wrapper), prettifyKeys); } else { safePut(map, getCompositeWrapper(entry.getKey()), wrapper, prettifyKeys); } } return map; } if (value instanceof Collection) { Collection<?> composite = (Collection<?>) value; List<Object> list = new ArrayList<Object>(); for (Object element : composite) { list.add(getCompositeWrapper(element)); } return list; } if (value.getClass().isArray()) { List<Object> list = new ArrayList<Object>(); for (Object element : (Object[]) value) { list.add(getCompositeWrapper(element)); } return list; } return value; } private void safePut(Map<Object, Object> map, Object key, Object value) { safePut(map, key, value, true); } private void verySafePut(Map<? extends Object, Object> map, Object key, Object value) { @SuppressWarnings("unchecked") Map<Object, Object> target = (Map<Object, Object>) map; safePut(target, key, value); } private void safePut(Map<Object, Object> map, Object key, Object value, boolean prettifyKeys) { Object property = key; if (key instanceof String && prettifyKeys) { property = StringUtils.camelToUnderscore((String) key); } // Don't prettify system property keys in case user has added upper case properties map.put(property, getCompositeWrapper(value, prettifyKeys && !key.equals("SystemProperties"))); } private Object getValue(Object wrapper) { @SuppressWarnings("unchecked") Map<Object, Object> map = (Map<Object, Object>) wrapper; return map.get("value"); } private String getKey(Object wrapper) { @SuppressWarnings("unchecked") Map<String, String> map = (Map<String, String>) wrapper; return map.get("key"); } private boolean isKeyValuePair(Object wrapper) { if (!(wrapper instanceof Map)) { return false; } @SuppressWarnings("unchecked") Map<Object, Object> map = (Map<Object, Object>) wrapper; if (map.size() > 2) { return false; } if (map.containsKey("key") && map.containsKey("value")) { return true; } return false; } }