AbstractAppender (Logback Appenders 2.4.1 API)

java.lang.Object
- ch.qos.logback.core.spi.ContextAwareBase
- - ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
  - - com.kdgregory.logback.aws.internal.AbstractAppender<WriterConfigType,AppenderStatsType,AppenderStatsMXBeanType,LogbackEventType>

All Implemented Interfaces:

ch.qos.logback.core.Appender<LogbackEventType>, ch.qos.logback.core.spi.ContextAware, ch.qos.logback.core.spi.FilterAttachable<LogbackEventType>, ch.qos.logback.core.spi.LifeCycle

Direct Known Subclasses:

CloudWatchAppender, KinesisAppender, SNSAppender
```
public abstract class AbstractAppender<WriterConfigType,AppenderStatsType extends AbstractWriterStatistics,AppenderStatsMXBeanType,LogbackEventType>
extends ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
```
Common implementation code that's shared between appenders.
For the most part, appenders have the same behavior: they initialize, transform log messages, and shut down. Most of the code to do that lives here, with a few hooks that are implemented in the appender proper.
Some behaviors, such as log rotation, are implemented here even if they are not supported by all appenders. The appenders that do not support those behaviors are responsible for disabling them. For example, an appender that does not support log rotation should throw if setRotationMode(java.lang.String) is called.
Most of the member variables defined by this class are protected. This is intended to support testing. If you decide to subclass and access those variables, well, this is an internal class: they may go away.
Note: this appender is built on UnsynchronizedAppenderBase, which is perhaps unnecessary (if you're worried about contention you shouldn't be doing a lot of logging). However, there are some critical sections within append(LogbackEventType), and these are protected by internal lock objects.

Field Summary

Fields
Modifier and Type	Field and Description
`protected AppenderStatsType`	`appenderStats`
`protected String`	`assumedRole`
`protected long`	`batchDelay`
`protected String`	`clientEndpoint`
`protected String`	`clientFactory`
`protected String`	`clientRegion`
`protected DiscardAction`	`discardAction`
`protected int`	`discardThreshold`
`protected InternalLogger`	`internalLogger`
`protected long`	`lastRotationTimestamp`
`protected ch.qos.logback.core.Layout<LogbackEventType>`	`layout`
`protected int`	`messagesSinceLastRotation`
`protected long`	`rotationInterval`
`protected RotationMode`	`rotationMode`
`protected AtomicInteger`	`sequence`
`protected boolean`	`synchronous`
`protected ThreadFactory`	`threadFactory`
`protected boolean`	`truncateOversizeMessages`
`protected boolean`	`useShutdownHook`
`protected LogWriter`	`writer`
`protected WriterFactory<WriterConfigType,AppenderStatsType>`	`writerFactory`

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
`AbstractAppender(ThreadFactory threadFactory, WriterFactory<WriterConfigType,AppenderStatsType> writerFactory, AppenderStatsType appenderStats, Class<AppenderStatsMXBeanType> appenderStatsMXBeanClass)`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`append(LogbackEventType event)`
`protected abstract WriterConfigType`	`generateWriterConfig()` Called just before a writer is created, so that the subclass can perform substitutions on the configuration.
`AppenderStatsType`	`getAppenderStatistics()` Returns the appender statistics object.
`String`	`getAssumedRole()` Returns the `assumedRole` configuration property.
`long`	`getBatchDelay()` Returns the `batchDelay` configuration property.
`String`	`getClientEndpoint()` Returns the `clientEndpoint` configuration property.
`String`	`getClientFactory()` Returns the `clientFactory` configuration property.
`String`	`getClientRegion()` Returns the `clientRegion` configuration property.
`String`	`getDiscardAction()` Returns the `discardAction` configuration property.
`int`	`getDiscardThreshold()` Returns the `discardThreshold` configuration property.
`long`	`getRotationInterval()` Returns the `rotationInterval` configuration property.
`String`	`getRotationMode()` Returns the `rotationMode` configuration property.
`int`	`getSequence()` Returns the current `sequence` value (which will be updated each time the appender rotates).
`boolean`	`getSynchronous()` Returns the `synchronous` configuration property.
`boolean`	`getTruncateOversizeMessages()` Returns the `truncateOversizeMessages` configuration property.
`boolean`	`getUseShutdownHook()` Returns the `useShutdownHook` configuration property.
`protected void`	`registerStatisticsBean()` Registers the appender statistics with JMX.
`protected void`	`rotate()` Rotates the log writer.
`void`	`setAssumedRole(String value)` Sets the `assumedRole` configuration property.
`void`	`setBatchDelay(long value)` Sets the `batchDelay` configuration property.
`void`	`setClientEndpoint(String value)` Sets the `clientEndpoint` configuration property.
`void`	`setClientFactory(String value)` Sets the `discardAction` configuration property.
`void`	`setClientRegion(String value)` Sets the `clientRegion` configuration property.
`void`	`setDiscardAction(String value)` Sets the `discardAction` configuration property.
`void`	`setDiscardThreshold(int value)` Sets the `discardThreshold` configuration property.
`void`	`setLayout(ch.qos.logback.core.Layout<LogbackEventType> layout)` Sets the layout manager for this appender.
`void`	`setName(String name)`
`void`	`setRotationInterval(long value)` Sets the `rotationInterval` configuration property.
`protected void`	`setRotationMode(String value)` Sets the `rotationMode` configuration property.
`void`	`setSequence(int value)` Sets the `sequence` configuration property.
`void`	`setSynchronous(boolean value)` Sets the `synchronous` configuration property.
`void`	`setTruncateOversizeMessages(boolean value)` Sets the `truncateOversizeMessages` configuration property.
`void`	`setUseShutdownHook(boolean value)` Sets the `useShutdownHook` configuration property.
`protected boolean`	`shouldRotate(long now)` Determines whether the appender should rotate its writer.
`void`	`start()`
`void`	`stop()`
`protected void`	`unregisterStatisticsBean()` Unregisters the appender statistics from JMX.

Methods inherited from class ch.qos.logback.core.UnsynchronizedAppenderBase
addFilter, clearAllFilters, doAppend, getCopyOfAttachedFiltersList, getFilterChainDecision, getName, isStarted, 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
  - threadFactory
```
protected ThreadFactory threadFactory
```
  - writerFactory
```
protected WriterFactory<WriterConfigType,AppenderStatsType extends AbstractWriterStatistics> writerFactory
```
  - internalLogger
```
protected InternalLogger internalLogger
```
  - appenderStats
```
protected AppenderStatsType extends AbstractWriterStatistics appenderStats
```
  - writer
```
protected volatile LogWriter writer
```
  - layout
```
protected ch.qos.logback.core.Layout<LogbackEventType> layout
```
  - lastRotationTimestamp
```
protected volatile long lastRotationTimestamp
```
  - messagesSinceLastRotation
```
protected volatile int messagesSinceLastRotation
```
  - synchronous
```
protected boolean synchronous
```
  - batchDelay
```
protected long batchDelay
```
  - truncateOversizeMessages
```
protected boolean truncateOversizeMessages
```
  - discardThreshold
```
protected int discardThreshold
```
  - discardAction
```
protected DiscardAction discardAction
```
  - rotationMode
```
protected volatile RotationMode rotationMode
```
  - rotationInterval
```
protected volatile long rotationInterval
```
  - sequence
```
protected AtomicInteger sequence
```
  - assumedRole
```
protected String assumedRole
```
  - clientFactory
```
protected String clientFactory
```
  - clientRegion
```
protected String clientRegion
```
  - clientEndpoint
```
protected String clientEndpoint
```
  - useShutdownHook
```
protected boolean useShutdownHook
```
- Constructor Detail
  - AbstractAppender
```
public AbstractAppender(ThreadFactory threadFactory,
                        WriterFactory<WriterConfigType,AppenderStatsType> writerFactory,
                        AppenderStatsType appenderStats,
                        Class<AppenderStatsMXBeanType> appenderStatsMXBeanClass)
```
- Method Detail
  - setName
```
public void setName(String name)
```
    Specified by:
    
    setName in interface ch.qos.logback.core.Appender<LogbackEventType>
    
    Overrides:
    
    setName in class ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
  - setLayout
```
public void setLayout(ch.qos.logback.core.Layout<LogbackEventType> layout)
```
    Sets the layout manager for this appender. Note that we do not use an Encoder; it is a knob that doesn't need to be turned.
  - setRotationMode
```
protected void setRotationMode(String value)
```
    Sets the rotationMode configuration property.
    This method must be explicitly overridden and made public by appenders that support rotation.
  - getRotationMode
```
public String getRotationMode()
```
    Returns the rotationMode configuration property.
  - setRotationInterval
```
public void setRotationInterval(long value)
```
    Sets the rotationInterval configuration property.
  - getRotationInterval
```
public long getRotationInterval()
```
    Returns the rotationInterval configuration property.
  - setSequence
```
public void setSequence(int value)
```
    Sets the sequence configuration property.
  - getSequence
```
public int getSequence()
```
    Returns the current sequence value (which will be updated each time the appender rotates).
  - setSynchronous
```
public void setSynchronous(boolean value)
```
    Sets the synchronous configuration property. This can only be done at the time of configuration, not once the appender is operating.
  - getSynchronous
```
public boolean getSynchronous()
```
    Returns the synchronous configuration property.
  - setBatchDelay
```
public void setBatchDelay(long value)
```
    Sets the batchDelay configuration property.
  - getBatchDelay
```
public long getBatchDelay()
```
    Returns the batchDelay configuration property.
  - setTruncateOversizeMessages
```
public void setTruncateOversizeMessages(boolean value)
```
    Sets the truncateOversizeMessages configuration property.
  - getTruncateOversizeMessages
```
public boolean getTruncateOversizeMessages()
```
    Returns the truncateOversizeMessages configuration property.
  - setDiscardThreshold
```
public void setDiscardThreshold(int value)
```
    Sets the discardThreshold configuration property.
  - getDiscardThreshold
```
public int getDiscardThreshold()
```
    Returns the discardThreshold configuration property.
  - setDiscardAction
```
public void setDiscardAction(String value)
```
    Sets the discardAction configuration property.
  - getDiscardAction
```
public String getDiscardAction()
```
    Returns the discardAction configuration property.
  - setAssumedRole
```
public void setAssumedRole(String value)
```
    Sets the assumedRole configuration property.
    Calling this method after the writer has been initialized will have no effect until the next log rotation.
  - getAssumedRole
```
public String getAssumedRole()
```
    Returns the assumedRole configuration property.
  - setClientFactory
```
public void setClientFactory(String value)
```
    Sets the discardAction configuration property.
    Calling this method after the writer has been initialized will have no effect until the next log rotation.
  - getClientFactory
```
public String getClientFactory()
```
    Returns the clientFactory configuration property.
  - setClientRegion
```
public void setClientRegion(String value)
```
    Sets the clientRegion configuration property.
  - getClientRegion
```
public String getClientRegion()
```
    Returns the clientRegion configuration property.
  - setClientEndpoint
```
public void setClientEndpoint(String value)
```
    Sets the clientEndpoint configuration property.
  - getClientEndpoint
```
public String getClientEndpoint()
```
    Returns the clientEndpoint configuration property.
  - setUseShutdownHook
```
public void setUseShutdownHook(boolean value)
```
    Sets the useShutdownHook configuration property.
  - getUseShutdownHook
```
public boolean getUseShutdownHook()
```
    Returns the useShutdownHook configuration property.
  - getAppenderStatistics
```
public AppenderStatsType getAppenderStatistics()
```
    Returns the appender statistics object.
  - start
```
public void start()
```
    Specified by:
    
    start in interface ch.qos.logback.core.spi.LifeCycle
    
    Overrides:
    
    start in class ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
  - stop
```
public void stop()
```
    Specified by:
    
    stop in interface ch.qos.logback.core.spi.LifeCycle
    
    Overrides:
    
    stop in class ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
  - append
```
protected void append(LogbackEventType event)
```
    Specified by:
    
    append in class ch.qos.logback.core.UnsynchronizedAppenderBase<LogbackEventType>
  - rotate
```
protected void rotate()
```
    Rotates the log writer. This will create in a new writer thread, with the pre-rotation writer shutting down after processing all messages in its queue.
  - generateWriterConfig
```
protected abstract WriterConfigType generateWriterConfig()
```
    Called just before a writer is created, so that the subclass can perform substitutions on the configuration.
  - registerStatisticsBean
```
protected void registerStatisticsBean()
```
    Registers the appender statistics with JMX. Logs but otherwise ignores failure.
    The name for the bean is consistent with the Log4J LayoutDynamicMBean, so that it will appear in the hierarchy under the appender.
    Note: this method is protected so that it can be avoided during unit tests.
  - unregisterStatisticsBean
```
protected void unregisterStatisticsBean()
```
    Unregisters the appender statistics from JMX. This is called when the appender is closed. Logs but otherwise ignores failure.
    Note: this method is protected so that it can be avoided during unit tests.
  - shouldRotate
```
protected boolean shouldRotate(long now)
```
    Determines whether the appender should rotate its writer. This is called on every append, so should be as performant as possible. Subclasses that don't rotate should override and return false (Hotspot will quickly inline them).

Class AbstractAppender<WriterConfigType,AppenderStatsType extends AbstractWriterStatistics,AppenderStatsMXBeanType,LogbackEventType>

Field Summary

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

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

Field Detail

threadFactory

writerFactory

internalLogger

appenderStats

writer

layout

lastRotationTimestamp

messagesSinceLastRotation

synchronous

batchDelay

truncateOversizeMessages

discardThreshold

discardAction

rotationMode

rotationInterval

sequence

assumedRole

clientFactory

clientRegion

clientEndpoint

useShutdownHook

Constructor Detail

AbstractAppender

Method Detail

setName

setLayout

setRotationMode

getRotationMode

setRotationInterval

getRotationInterval

setSequence

getSequence

setSynchronous

getSynchronous

setBatchDelay

getBatchDelay

setTruncateOversizeMessages

getTruncateOversizeMessages

setDiscardThreshold

getDiscardThreshold

setDiscardAction

getDiscardAction

setAssumedRole

getAssumedRole

setClientFactory

getClientFactory

setClientRegion

getClientRegion

setClientEndpoint

getClientEndpoint

setUseShutdownHook

getUseShutdownHook

getAppenderStatistics

start

stop

append

rotate

generateWriterConfig

registerStatisticsBean

unregisterStatisticsBean

shouldRotate