package com.atlassian.plugin.jmx;
   
   import java.lang.management.ManagementFactory;
   import java.util.Hashtable;
   import java.util.concurrent.atomic.AtomicInteger;
   
   import javax.management.InstanceAlreadyExistsException;
   import javax.management.InstanceNotFoundException;
   import javax.management.MBeanRegistrationException;
  import javax.management.MalformedObjectNameException;
  import javax.management.NotCompliantMBeanException;
  import javax.management.ObjectInstance;
  import javax.management.ObjectName;
  
  import com.google.common.collect.ImmutableMap;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class JmxUtil
  {
      private static final Logger log = LoggerFactory.getLogger(JmxUtil.class);
  
      private static final String DOMAIN = "com.atlassian.plugin";
  
      /**
       * Obtain a JMX ObjectName for a new instance of a given type.
       *
       * @param counter a counter used to ensure a unique instance id amongst instances with given type.
       * @param type the friendly type name for the instance.
       * @return a JMX ObjectName for the instance, or null if creation fails.
       */
      public static ObjectName objectName(final AtomicInteger counter, final String type)
      {
          try
          {
              final String instance = Integer.toString(counter.getAndIncrement());
              return new ObjectName(DOMAIN, new Hashtable<String, String>(ImmutableMap.of("instance", instance, "type", type)));
          }
          catch(final MalformedObjectNameException emon)
          {
              log.warn("Failed to create ObjectName: ", emon.getMessage());
          }
          return null;
      }
  
      /**
       * Register a JMX MBean against a given ObjectName.
       * <p/>
       * This is simply an error logging wrapper around {@link javax.management.MBeanServer#registerMBean}.
       *
       * @param object the MBean implementation to register.
       * @param objectName the ObjectName to register against.
       * @return the ObjectInstance encapsulating the registration, or null if registration failed.
       */
      public static ObjectInstance register(final Object object, final ObjectName objectName)
      {
          try
          {
              if (null != objectName)
              {
                  return ManagementFactory.getPlatformMBeanServer().registerMBean(object, objectName);
              }
              else
              {
                  log.warn("Failed to register, objectName null");
              }
          }
          catch (final InstanceAlreadyExistsException eiae)
          {
              log.warn("Failed to register, instance already exists: ", eiae.getMessage());
          }
          catch (final MBeanRegistrationException emr)
          {
              log.warn("Failed to register, registration exception: ", emr.getMessage());
          }
          catch (final NotCompliantMBeanException encm)
          {
              log.warn("Failed to register, not compliant: ", encm.getMessage());
          }
          return null;
      }
  
      /**
       * Unregister the JMX MBean with a given ObjectName.
       * <p/>
       * This is simply an error logging wrapper around {@link javax.management.MBeanServer#unregisterMBean}.
       *
       * @param objectName the ObjectName of the MBean to unregister.
       * @return true if unregister succeeded, or false if unregister failed.
       */
      public static boolean unregister(final ObjectName objectName)
      {
          try
          {
              ManagementFactory.getPlatformMBeanServer().unregisterMBean(objectName);
              return true;
          }
          catch (final InstanceNotFoundException einf)
         {
             log.warn("Failed to unregister, instance not found: ", einf.getMessage());
         }
         catch (final MBeanRegistrationException emr)
         {
             log.warn("Failed to unregister, registration exception: ", emr.getMessage());
         }
         return false;
     }
 }