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WriterAppender Class Reference

WriterAppender appends log events to a standard output stream. More...

Inheritance diagram for WriterAppender:
AppenderSkeleton Appender ObjectImpl OptionHandler Object Object ConsoleAppender FileAppender RollingFileAppenderSkeleton DailyRollingFileAppender RollingFileAppender RollingFileAppender

Public Member Functions

 WriterAppender ()
 This default constructor does nothing. More...
 
 ~WriterAppender ()
 
virtual void activateOptions (log4cxx::helpers::Pool &pool)
 Derived appenders should override this method if option structure requires it. More...
 
void setImmediateFlush (bool value)
 If the ImmediateFlush option is set to true, the appender will flush at the end of each write. More...
 
bool getImmediateFlush () const
 Returns value of the ImmediateFlush option. More...
 
virtual void append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)
 This method is called by the AppenderSkeleton::doAppend method. More...
 
virtual void close ()
 Close this appender instance. More...
 
LogString getEncoding () const
 
void setEncoding (const LogString &value)
 
void setOption (const LogString &option, const LogString &value)
 Set option to value. More...
 
void setWriter (const log4cxx::helpers::WriterPtr &writer)
 
virtual bool requiresLayout () const
 Configurators call this method to determine if the appender requires a layout. More...
 
- Public Member Functions inherited from AppenderSkeleton
 AppenderSkeleton ()
 
 AppenderSkeleton (const LayoutPtr &layout)
 
void addRef () const
 
void releaseRef () const
 
void finalize ()
 Finalize this appender by calling the derived class' close method. More...
 
void addFilter (const spi::FilterPtr &newFilter)
 Add a filter to end of the filter list. More...
 
void clearFilters ()
 Clear the filters chain. More...
 
const spi::ErrorHandlerPtrgetErrorHandler () const
 Return the currently set spi::ErrorHandler for this Appender. More...
 
spi::FilterPtr getFilter () const
 Returns the head Filter. More...
 
const spi::FilterPtrgetFirstFilter () const
 Return the first filter in the filter chain for this Appender. More...
 
LayoutPtr getLayout () const
 Returns the layout of this appender. More...
 
LogString getName () const
 Returns the name of this Appender. More...
 
const LevelPtrgetThreshold ()
 Returns this appenders threshold level. More...
 
bool isAsSevereAsThreshold (const LevelPtr &level) const
 Check whether the message level is below the appender's threshold. More...
 
void doAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)
 This method performs threshold checks and invokes filters before delegating actual logging to the subclasses specific AppenderSkeleton::append method. More...
 
void setErrorHandler (const spi::ErrorHandlerPtr &eh)
 Set the ErrorHandler for this Appender. More...
 
void setLayout (const LayoutPtr &layout1)
 Set the layout for this appender. More...
 
void setName (const LogString &name1)
 Set the name of this Appender. More...
 
void setThreshold (const LevelPtr &threshold)
 Set the threshold level. More...
 
- Public Member Functions inherited from Appender
virtual ~Appender ()
 
- Public Member Functions inherited from OptionHandler
virtual ~OptionHandler ()
 
- Public Member Functions inherited from Object
virtual const helpers::ClassgetClass () const
 
virtual ~Object ()
 
virtual bool instanceof (const Class &clazz) const =0
 
virtual const void * cast (const Class &clazz) const =0
 
- Public Member Functions inherited from ObjectImpl
 ObjectImpl ()
 
virtual ~ObjectImpl ()
 
void addRef () const
 
void releaseRef () const
 

Protected Member Functions

 WriterAppender (const LayoutPtr &layout, log4cxx::helpers::WriterPtr &writer)
 
 WriterAppender (const LayoutPtr &layout)
 
virtual bool checkEntryConditions () const
 This method determines if there is a sense in attempting to append. More...
 
void closeWriter ()
 Close the underlying log4cxx::helpers::Writer. More...
 
virtual log4cxx::helpers::WriterPtr createWriter (log4cxx::helpers::OutputStreamPtr &os)
 Returns an OutputStreamWriter when passed an OutputStream. More...
 
virtual void subAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)
 Actual writing occurs here. More...
 
virtual void writeFooter (log4cxx::helpers::Pool &p)
 Write a footer as produced by the embedded layout's Layout::appendFooter method. More...
 
virtual void writeHeader (log4cxx::helpers::Pool &p)
 Write a header as produced by the embedded layout's Layout::appendHeader method. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from Object
static const helpers::ClassgetStaticClass ()
 
static const
log4cxx::helpers::ClassRegistration
registerClass ()
 
- Protected Attributes inherited from AppenderSkeleton
LayoutPtr layout
 The layout variable does not need to be set if the appender implementation has its own layout. More...
 
LogString name
 Appenders are named. More...
 
LevelPtr threshold
 There is no level threshold filtering by default. More...
 
spi::ErrorHandlerPtr errorHandler
 It is assumed and enforced that errorHandler is never null. More...
 
spi::FilterPtr headFilter
 The first filter in the filter chain. More...
 
spi::FilterPtr tailFilter
 The last filter in the filter chain. More...
 
bool closed
 Is this appender closed? More...
 
log4cxx::helpers::Pool pool
 
log4cxx::helpers::Mutex mutex
 
- Protected Attributes inherited from ObjectImpl
unsigned int volatile ref
 

Detailed Description

WriterAppender appends log events to a standard output stream.

Constructor & Destructor Documentation

This default constructor does nothing.

WriterAppender ( const LayoutPtr layout,
log4cxx::helpers::WriterPtr &  writer 
)
protected
WriterAppender ( const LayoutPtr layout)
protected

Member Function Documentation

virtual void activateOptions ( log4cxx::helpers::Pool pool)
virtual

Derived appenders should override this method if option structure requires it.

Reimplemented from AppenderSkeleton.

Reimplemented in DailyRollingFileAppender, FileAppender, RollingFileAppender, RollingFileAppenderSkeleton, and ConsoleAppender.

virtual void append ( const spi::LoggingEventPtr event,
log4cxx::helpers::Pool p 
)
virtual

This method is called by the AppenderSkeleton::doAppend method.

If the output stream exists and is writable then write a log statement to the output stream. Otherwise, write a single warning message to stderr.

The format of the output will depend on this appender's layout.

Implements AppenderSkeleton.

virtual bool checkEntryConditions ( ) const
protectedvirtual

This method determines if there is a sense in attempting to append.

It checks whether there is a set output target and also if there is a set layout. If these checks fail, then the boolean value false is returned.

virtual void close ( )
virtual

Close this appender instance.

The underlying stream or writer is also closed.

Closed appenders cannot be reused.

Implements Appender.

Reimplemented in RollingFileAppenderSkeleton.

void closeWriter ( )
protected

Close the underlying log4cxx::helpers::Writer.

virtual log4cxx::helpers::WriterPtr createWriter ( log4cxx::helpers::OutputStreamPtr &  os)
protectedvirtual

Returns an OutputStreamWriter when passed an OutputStream.

The encoding used will depend on the value of the encoding property. If the encoding value is specified incorrectly the writer will be opened using the default system encoding (an error message will be printed to the loglog.

Reimplemented in RollingFileAppenderSkeleton.

LogString getEncoding ( ) const
bool getImmediateFlush ( ) const
inline

Returns value of the ImmediateFlush option.

virtual bool requiresLayout ( ) const
virtual

Configurators call this method to determine if the appender requires a layout.

If this method returns true, meaning that layout is required, then the configurator will configure an layout using the configuration information at its disposal. If this method returns false, meaning that a layout is not required, then layout configuration will be skipped even if there is available layout configuration information at the disposal of the configurator..

In the rather exceptional case, where the appender implementation admits a layout but can also work without it, then the appender should return true.

Implements Appender.

void setEncoding ( const LogString value)
void setImmediateFlush ( bool  value)

If the ImmediateFlush option is set to true, the appender will flush at the end of each write.

This is the default behavior. If the option is set to false, then the underlying stream can defer writing to physical medium to a later time.

Avoiding the flush operation at the end of each append results in a performance gain of 10 to 20 percent. However, there is safety tradeoff involved in skipping flushing. Indeed, when flushing is skipped, then it is likely that the last few log events will not be recorded on disk when the application exits. This is a high price to pay even for a 20% performance gain.

void setOption ( const LogString option,
const LogString value 
)
virtual

Set option to value.

The handling of each option depends on the OptionHandler instance. Some options may become active immediately whereas other may be activated only when activateOptions is called.

Reimplemented from AppenderSkeleton.

void setWriter ( const log4cxx::helpers::WriterPtr &  writer)

Sets the Writer where the log output will go. The specified Writer must be opened by the user and be writable.

The java.io.Writer will be closed when the appender instance is closed.

WARNING: Logging to an unopened Writer will fail.

Parameters
writerAn already opened Writer.
virtual void subAppend ( const spi::LoggingEventPtr event,
log4cxx::helpers::Pool p 
)
protectedvirtual

Actual writing occurs here.

Reimplemented in RollingFileAppenderSkeleton.

virtual void writeFooter ( log4cxx::helpers::Pool p)
protectedvirtual

Write a footer as produced by the embedded layout's Layout::appendFooter method.

virtual void writeHeader ( log4cxx::helpers::Pool p)
protectedvirtual

Write a header as produced by the embedded layout's Layout::appendHeader method.


The documentation for this class was generated from the following file: