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.blueprint.impl;
  
  import javax.management.InstanceAlreadyExistsException;
  import javax.management.InstanceNotFoundException;
  import javax.management.MBeanRegistrationException;
  import javax.management.MBeanServer;
  import javax.management.NotCompliantMBeanException;
  import javax.management.ObjectName;
  import javax.management.StandardMBean;
  
  import org.apache.aries.jmx.blueprint.BlueprintMetadataMBean;
  import org.apache.aries.jmx.blueprint.BlueprintStateMBean;
  import org.osgi.framework.BundleActivator;
  import org.osgi.framework.BundleContext;
  import org.osgi.framework.ServiceReference;
  import org.osgi.util.tracker.ServiceTracker;
  import org.osgi.util.tracker.ServiceTrackerCustomizer;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class Activator implements BundleActivator {
  
      private static final Logger LOGGER = LoggerFactory.getLogger("org.apache.aries.jmx.blueprint");
  
      protected BundleContext bundleContext;
  
      protected ObjectName blueprintStateName;
      protected ObjectName blueprintMetadataName;
  
      protected ServiceTracker mbeanServiceTracker;
  
      public void start(BundleContext context) throws Exception {
          this.bundleContext = context;
          this.blueprintStateName = new ObjectName(BlueprintStateMBean.OBJECTNAME);
          this.blueprintMetadataName = new ObjectName(BlueprintMetadataMBean.OBJECTNAME);
  
          // create MBeanServerServiceTracker
          // if there has been already a MBeanServer Service in place, this MBeanServerServiceTracker won't miss it
          mbeanServiceTracker = new ServiceTracker(bundleContext, MBeanServer.class.getCanonicalName(),
                  new MBeanServerServiceTracker());
          LOGGER.debug("Awaiting MBeanServer service registration");
          mbeanServiceTracker.open();
      }
  
      public void stop(BundleContext context) throws Exception {
          mbeanServiceTracker.close();
      }
  
      class MBeanServerServiceTracker implements ServiceTrackerCustomizer {
  
          public Object addingService(ServiceReference servicereference) {
              try {
                  LOGGER.debug("Adding MBeanServer: {}", servicereference);
                  final MBeanServer mbeanServer = (MBeanServer) bundleContext.getService(servicereference);
                  if (mbeanServer != null) {
                      Activator.this.registerMBeans(mbeanServer);
                  }
                  return mbeanServer;
              } catch (RuntimeException e) {
                  LOGGER.error("uncaught exception in addingService", e);
                  throw e;
              }
          }
  
          public void removedService(ServiceReference servicereference, Object obj) {
              try {
                  LOGGER.debug("Removing MBeanServer: {}", servicereference);
                  Activator.this.deregisterMBeans((MBeanServer) obj);
              } catch (Throwable e) {
                  LOGGER.debug("uncaught exception in removedService", e);
              }
          }
  
          public void modifiedService(ServiceReference servicereference, Object obj) {
              // no op
          }
  
      }
  
      protected void registerMBeans(MBeanServer mbeanServer) {
          // register BlueprintStateMBean to MBean server
          LOGGER.debug("Registering bundle state monitor with MBeanServer: {} with name: {}",
                          mbeanServer, blueprintStateName);
          try {
              StandardMBean blueprintState = new RegistrableStandardEmitterMBean(new BlueprintState(bundleContext), BlueprintStateMBean.class);
              mbeanServer.registerMBean(blueprintState, blueprintStateName);
          } catch (InstanceAlreadyExistsException e) {
              LOGGER.debug("Cannot register BlueprintStateMBean");
          } catch (MBeanRegistrationException e) {
              LOGGER.error("Cannot register BlueprintStateMBean", e);
          } catch (NotCompliantMBeanException e) {
              LOGGER.error("Cannot register BlueprintStateMBean", e);
          }
  
          // register BlueprintMetadataMBean to MBean server
          LOGGER.debug("Registering bundle metadata monitor with MBeanServer: {} with name: {}",
                      mbeanServer, blueprintMetadataName);
          try {
              StandardMBean blueprintMetadata = new StandardMBean(new BlueprintMetadata(bundleContext), BlueprintMetadataMBean.class);
              mbeanServer.registerMBean(blueprintMetadata, blueprintMetadataName);
          } catch (InstanceAlreadyExistsException e) {
              LOGGER.debug("Cannot register BlueprintMetadataMBean");
          } catch (MBeanRegistrationException e) {
              LOGGER.error("Cannot register BlueprintMetadataMBean", e);
          } catch (NotCompliantMBeanException e) {
              LOGGER.error("Cannot register BlueprintMetadataMBean", e);
          }
      }
  
      protected void deregisterMBeans(MBeanServer mbeanServer) {
          // unregister BlueprintStateMBean from MBean server
          try {
              mbeanServer.unregisterMBean(blueprintStateName);
          } catch (InstanceNotFoundException e) {
              LOGGER.debug("BlueprintStateMBean not found on deregistration");
          } catch (MBeanRegistrationException e) {
              LOGGER.error("BlueprintStateMBean deregistration problem");
          }
  
          // unregister BlueprintMetadataMBean from MBean server
          try {
              mbeanServer.unregisterMBean(blueprintMetadataName);
          } catch (InstanceNotFoundException e) {
              LOGGER.debug("BlueprintMetadataMBean not found on deregistration");
          } catch (MBeanRegistrationException e) {
              LOGGER.error("BlueprintMetadataMBean deregistration problem");
          }
      }
  
  }
  