ch.qos.logback.core

Class AsyncAppenderBase<E>

java.lang.Object

ch.qos.logback.core.spi.ContextAwareBase

ch.qos.logback.core.UnsynchronizedAppenderBase<E>

ch.qos.logback.core.AsyncAppenderBase<E>

Type Parameters:

E -

All Implemented Interfaces:

Appender<E>, AppenderAttachable<E>, ContextAware, FilterAttachable<E>, LifeCycle

public class AsyncAppenderBase<E>
extends UnsynchronizedAppenderBase<E>
implements AppenderAttachable<E>

This appender and derived classes, log events asynchronously. In order to avoid loss of logging events, this appender should be closed. It is the user's responsibility to close appenders, typically at the end of the application lifecycle.

This appender buffers events in a BlockingQueue. Worker thread created by this appender takes events from the head of the queue, and dispatches them to the single appender attached to this appender.

Please refer to the logback manual for further information about this appender.

Since:

1.0.4

Author:

Ceki Gülcü, Torsten Juergeleit

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_QUEUE_SIZE The default buffer size.

Fields inherited from class ch.qos.logback.core.UnsynchronizedAppenderBase

name, started

Fields inherited from class ch.qos.logback.core.spi.ContextAwareBase

context

Constructor Summary

Constructors

Constructor and Description
AsyncAppenderBase()

Method Summary

Methods

Modifier and Type	Method and Description
void	addAppender(Appender<E> newAppender) Add an appender.
protected void	append(E eventObject)
void	detachAndStopAllAppenders() Detach and processPriorToRemoval all previously added appenders.
boolean	detachAppender(Appender<E> eAppender) Detach the appender passed as parameter from the list of appenders.
boolean	detachAppender(String name) Detach the appender with the name passed as parameter from the list of appenders.
Appender<E>	getAppender(String name) Get an appender by name.
int	getDiscardingThreshold()
int	getNumberOfElementsInQueue() Returns the number of elements currently in the blocking queue.
int	getQueueSize()
int	getRemainingCapacity() The remaining capacity available in the blocking queue.
boolean	isAttached(Appender<E> eAppender) Returns true if the specified appender is in list of attached attached, false otherwise.
protected boolean	isDiscardable(E eventObject) Is the eventObject passed as parameter discardable? The base class's implementation of this method always returns 'false' but sub-classes may (and do) override this method.
Iterator<Appender<E>>	iteratorForAppenders() Get an iterator for appenders contained in the parent object.
protected void	preprocess(E eventObject) Pre-process the event prior to queueing.
void	setDiscardingThreshold(int discardingThreshold)
void	setQueueSize(int queueSize)
void	start()
void	stop()

Methods inherited from class ch.qos.logback.core.UnsynchronizedAppenderBase

addFilter, clearAllFilters, doAppend, getCopyOfAttachedFiltersList, getFilterChainDecision, getName, isStarted, setName, toString

Methods inherited from class ch.qos.logback.core.spi.ContextAwareBase

addError, addError, addInfo, addInfo, addStatus, addWarn, addWarn, getContext, getDeclaredOrigin, getStatusManager, setContext

Methods inherited from class java.lang.Object

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

Methods inherited from interface ch.qos.logback.core.spi.ContextAware

addError, addError, addInfo, addInfo, addStatus, addWarn, addWarn, getContext, setContext

Field Detail

DEFAULT_QUEUE_SIZE

public static final int DEFAULT_QUEUE_SIZE

The default buffer size.

See Also:

Constant Field Values

Constructor Detail

AsyncAppenderBase

public AsyncAppenderBase()

Method Detail

isDiscardable

protected boolean isDiscardable(E eventObject)

Is the eventObject passed as parameter discardable? The base class's implementation of this method always returns 'false' but sub-classes may (and do) override this method.

Note that only if the buffer is nearly full are events discarded. Otherwise, when the buffer is "not full" all events are logged.

Parameters:

eventObject -

Returns:

- true if the event can be discarded, false otherwise

preprocess

protected void preprocess(E eventObject)

Pre-process the event prior to queueing. The base class does no pre-processing but sub-classes can override this behavior.

Parameters:

eventObject -

start

public void start()

Specified by:

start in interface LifeCycle

Overrides:

start in class UnsynchronizedAppenderBase<E>

stop

public void stop()

Specified by:

stop in interface LifeCycle

Overrides:

stop in class UnsynchronizedAppenderBase<E>

append

protected void append(E eventObject)

Specified by:

append in class UnsynchronizedAppenderBase<E>

getQueueSize

public int getQueueSize()

setQueueSize

public void setQueueSize(int queueSize)

getDiscardingThreshold

public int getDiscardingThreshold()

setDiscardingThreshold

public void setDiscardingThreshold(int discardingThreshold)

getNumberOfElementsInQueue

public int getNumberOfElementsInQueue()

Returns the number of elements currently in the blocking queue.

Returns:

number of elements currently in the queue.

getRemainingCapacity

public int getRemainingCapacity()

The remaining capacity available in the blocking queue.

Returns:

the remaining capacity

See Also:

java.util.concurrent.BlockingQueue#remainingCapacity()}

addAppender

public void addAppender(Appender<E> newAppender)

Description copied from interface: AppenderAttachable

Add an appender.

Specified by:

addAppender in interface AppenderAttachable<E>

iteratorForAppenders

public Iterator<Appender<E>> iteratorForAppenders()

Description copied from interface: AppenderAttachable

Get an iterator for appenders contained in the parent object.

Specified by:

iteratorForAppenders in interface AppenderAttachable<E>

getAppender

public Appender<E> getAppender(String name)

Description copied from interface: AppenderAttachable

Get an appender by name.

Specified by:

getAppender in interface AppenderAttachable<E>

isAttached

public boolean isAttached(Appender<E> eAppender)

Description copied from interface: AppenderAttachable

Returns true if the specified appender is in list of attached attached, false otherwise.

Specified by:

isAttached in interface AppenderAttachable<E>

detachAndStopAllAppenders

public void detachAndStopAllAppenders()

Description copied from interface: AppenderAttachable

Detach and processPriorToRemoval all previously added appenders.

Specified by:

detachAndStopAllAppenders in interface AppenderAttachable<E>

detachAppender

public boolean detachAppender(Appender<E> eAppender)

Description copied from interface: AppenderAttachable

Detach the appender passed as parameter from the list of appenders.

Specified by:

detachAppender in interface AppenderAttachable<E>

detachAppender

public boolean detachAppender(String name)

Description copied from interface: AppenderAttachable

Detach the appender with the name passed as parameter from the list of appenders.

Specified by:

detachAppender in interface AppenderAttachable<E>