content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.aries.jmx.whiteboard;
  
  import java.util.IdentityHashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  import javax.management.DynamicMBean;
  import javax.management.InstanceAlreadyExistsException;
  import javax.management.InstanceNotFoundException;
  import javax.management.MBeanRegistrationException;
  import javax.management.MBeanServer;
  import javax.management.NotCompliantMBeanException;
  import javax.management.ObjectInstance;
  import javax.management.ObjectName;
  import javax.management.StandardMBean;
  
  import org.apache.aries.jmx.util.shared.RegistrableStandardEmitterMBean;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  final class MBeanHolder {
  
      /** default log */
      private final Logger log = LoggerFactory.getLogger(getClass());
  
      private final Object mbean;
  
      private final ObjectName requestedObjectName;
  
      private final Map<MBeanServer, ObjectName> registrations;
  
      static <T> MBeanHolder create(final T mbean,
              final ObjectName requestedObjectName) {
          if (mbean instanceof DynamicMBean) {
              return new MBeanHolder(mbean, requestedObjectName);
          } else if (mbean == null) {
              return null;
          }
  
          Class<?> mbeanClass = mbean.getClass();
          @SuppressWarnings("unchecked") // This is all in aid of getting new StandardMBean to work.
          Class<T> mbeanInterface = (Class<T>) getMBeanInterface(mbeanClass);
          if (mbeanInterface == null) {
              return null;
          }
  
          if (mbeanInterface.getName().equals(
              mbeanClass.getName().concat("MBean")) || mbeanInterface.getName().equals(mbeanClass.getName().concat("MXBean")) ) {
              return new MBeanHolder(mbean, requestedObjectName);
          }
  
          try {
              StandardMBean stdMbean = new RegistrableStandardEmitterMBean(mbean, mbeanInterface);
              return new MBeanHolder(stdMbean, requestedObjectName);
          } catch (NotCompliantMBeanException e) {
              LoggerFactory.getLogger(MBeanHolder.class).error(
                  "create: Cannot create StandardMBean for " + mbean
                      + " of type " + mbeanClass + " for interface "
                      + mbeanInterface, e);
              return null;
          }
      }
  
      private static Class<?> getMBeanInterface(final Class<?> mbeanClass) {
          if (mbeanClass == null) {
              return null;
          }
  
          for (Class<?> i : mbeanClass.getInterfaces()) {
              if (i.getName().endsWith("MBean") || i.getName().endsWith("MXBean")) {
                  return i;
              }
  
              Class<?> mbeanInterface = getMBeanInterface(i);
              if (mbeanInterface != null) {
                  return mbeanInterface;
              }
          }
  
          if (mbeanClass.getSuperclass() != null) {
              return getMBeanInterface(mbeanClass.getSuperclass());
          }
  
          return null;
      }
  
      MBeanHolder(final Object mbean, final ObjectName requestedObjectName) {
          this.mbean = mbean;
          this.requestedObjectName = requestedObjectName;
          this.registrations = new IdentityHashMap<MBeanServer, ObjectName>();
      }
  
      void register(final MBeanServer server, String[] warnExceptions) {
          ObjectInstance instance;
          try {
              instance = server.registerMBean(mbean, requestedObjectName);
              registrations.put(server, instance.getObjectName());
          } catch (Exception e) {
              String exClass = e.getClass().getName();
              if (warnExceptions == null)
                  warnExceptions = new String[] {};
  
              for (String exCls : warnExceptions) {
                  if (exClass.equals(exCls)) {
                      log.warn("register: problem registering MBean " + mbean, e);
                      return;
                  }
              }
  
              if (e instanceof InstanceAlreadyExistsException ||
                      e instanceof MBeanRegistrationException ||
                      e instanceof NotCompliantMBeanException) {
                  log.error("register: Failure registering MBean " + mbean, e);
              } else if (e instanceof RuntimeException) {
                  throw ((RuntimeException) e);
              }
          }
      }
  
      void unregister(final MBeanServer server) {
          final ObjectName registeredName = registrations.remove(server);
          if (registeredName != null) {
              unregister(server, registeredName);
          }
      }
  
      void unregister() {
          for (Entry<MBeanServer, ObjectName> entry : registrations.entrySet()) {
              unregister(entry.getKey(), entry.getValue());
          }
          registrations.clear();
      }
  
      private void unregister(final MBeanServer server, final ObjectName name) {
          try {
              server.unregisterMBean(name);
          } catch (MBeanRegistrationException e) {
              log.error("unregister: preDeregister of " + name
                  + " threw an exception", e);
          } catch (InstanceNotFoundException e) {
              // not really expected !
              log.error("unregister: Unexpected unregistration problem of MBean "
                  + name, e);
          }
      }
  }
  