com.kdgregory.log4j.aws.internal.shared

Class JMXManager

java.lang.Object

com.kdgregory.log4j.aws.internal.shared.JMXManager

public class JMXManager
extends Object

This class ensures that appenders will be registered with any MBean servers where a StatisticsMBean instance has also been registered, regardless of the order that those objects are initialized/registered.

This object is implemented as an eagerly-instantiated singleton; for testing the implementation can be replaced. All methods are synchronized, to avoid race conditions between appender and StatisticsMBean registration.

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<String,AbstractAppenderStatistics>	appenderStatsBeans
protected Map<String,Class<?>>	appenderStatsBeanTypes
protected Map<StatisticsMBean,List<MBeanServer>>	knownServers

Constructor Summary

Constructors

Constructor and Description
JMXManager()

Method Summary

Modifier and Type	Method and Description
void	addAppender(String appenderName, AbstractAppenderStatistics statsBean, Class<?> statsBeanClass) Adds an appender's statsbean and its class to the internal tracking tables.
void	addStatisticsMBean(StatisticsMBean bean, MBeanServer server, ObjectName name) Adds relationship between a StatisticsMBean and an MBeanServer to the internal tables.
static JMXManager	getInstance()
protected void	registerAppenderBean(String appenderName, MBeanServer mbeanServer) Registers an appender's stats bean with a server.
void	removeAppender(String appenderName) Removes information about an appender from the internal tables and deregisters it from any MBeanServers.
void	removeStatisticsMBean(StatisticsMBean bean) Will deregister a StatisticsMBean instance from all known servers.
static void	reset(JMXManager newManager) Replaces the singleton instance with a new instance.
protected void	unregisterAppenderBean(String appenderName, MBeanServer mbeanServer) Deregisters an appender's stats bean from a server.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

knownServers

protected Map<StatisticsMBean,List<MBeanServer>> knownServers

appenderStatsBeans

protected Map<String,AbstractAppenderStatistics> appenderStatsBeans

appenderStatsBeanTypes

protected Map<String,Class<?>> appenderStatsBeanTypes

Constructor Detail

JMXManager

public JMXManager()

Method Detail

getInstance

public static JMXManager getInstance()

reset

public static void reset(JMXManager newManager)

Replaces the singleton instance with a new instance. This method is exposed for testing; it should never be called by application code.

addStatisticsMBean

public void addStatisticsMBean(StatisticsMBean bean,
                               MBeanServer server,
                               ObjectName name)

Adds relationship between a StatisticsMBean and an MBeanServer to the internal tables. If any appender beans are known, will register those beans with the same server.

The StatisticsMBean table is based on object identity. Attempting to add the same bean/server more than once is silently ignored (should never happen in the real world).

removeStatisticsMBean

public void removeStatisticsMBean(StatisticsMBean bean)

Will deregister a StatisticsMBean instance from all known servers.

addAppender

public void addAppender(String appenderName,
                        AbstractAppenderStatistics statsBean,
                        Class<?> statsBeanClass)

Adds an appender's statsbean and its class to the internal tracking tables. If there are known StatisticsMBean/MBeanServer associations, the appender's statistics bean will also be registered with those servers.

These tables are managed by appender name. Calling with the same name and same appender bean is silently ignored. Calling with the same name but a different appender bean is an error. In the real world, neither of these cases should happen, because the appender is registered during initialization.

removeAppender

public void removeAppender(String appenderName)

Removes information about an appender from the internal tables and deregisters it from any MBeanServers. This is normally called when the appender is closed.

registerAppenderBean

protected void registerAppenderBean(String appenderName,
                                    MBeanServer mbeanServer)

Registers an appender's stats bean with a server.

unregisterAppenderBean

protected void unregisterAppenderBean(String appenderName,
                                      MBeanServer mbeanServer)

Deregisters an appender's stats bean from a server.