Apache Log4cxx: log4cxx::WriterAppender Class Reference (original) (raw)

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

#include <[writerappender.h](writerappender%5F8h%5Fsource.html)>

Public Member Functions
	WriterAppender ()
	This default constructor does nothing.
	~WriterAppender ()
void	activateOptions (helpers::Pool &pool) override
	Derived appenders should override this method if option structure requires it.
void	setImmediateFlush (bool value)
	If the ImmediateFlush option is set to true, the appender will flush at the end of each write.
bool	getImmediateFlush () const
	Returns value of the ImmediateFlush option.
void	append (const spi::LoggingEventPtr &event, helpers::Pool &p) override
	This method is called by the AppenderSkeleton::doAppend method.
void	close () override
	Close this appender instance.
LogString	getEncoding () const
	The current encoding value.
void	setEncoding (const LogString &value)
	Set the encoding to value.
void	setOption (const LogString &option, const LogString &value) override
	Set option to value.
void	setWriter (const helpers::WriterPtr &writer)
const helpers::WriterPtr	getWriter () const
bool	requiresLayout () const override
	Configurators call this method to determine if the appender requires a layout.
Public Member Functions inherited from log4cxx::AppenderSkeleton
	AppenderSkeleton ()
	AppenderSkeleton (const LayoutPtr &layout)
virtual	~AppenderSkeleton ()
void	finalize ()
	Finalize this appender by calling the derived class' close method.
void	activateOptions (helpers::Pool &) override
	Activate the options that were previously set with calls to option setters.
void	setOption (const LogString &option, const LogString &value) override
	Set option to value.
void	addFilter (const spi::FilterPtr newFilter) override
	Add a filter to end of the filter list.
void	clearFilters () override
	Clear the filters chain.
const spi::ErrorHandlerPtr	getErrorHandler () const
	Return the currently set spi::ErrorHandler for this Appender.
spi::FilterPtr	getFilter () const override
	Returns the head Filter.
const spi::FilterPtr	getFirstFilter () const
	Return the first filter in the filter chain for this Appender.
LayoutPtr	getLayout () const override
	Returns the layout of this appender.
LogString	getName () const override
	Returns the name of this Appender.
const LevelPtr	getThreshold () const
	Returns this appenders threshold level.
bool	isAsSevereAsThreshold (const LevelPtr &level) const
	Check whether the message level is below the appender's threshold.
void	doAppend (const spi::LoggingEventPtr &event, helpers::Pool &pool) override
	This method performs threshold checks and invokes filters before delegating actual logging to the subclasses specific AppenderSkeleton::append method.
void	setErrorHandler (const spi::ErrorHandlerPtr eh)
	Set the ErrorHandler for this Appender.
void	setLayout (const LayoutPtr layout1) override
	Set the layout for this appender.
void	setName (const LogString &name1) override
	Set the name of this Appender.
void	setThreshold (const LevelPtr &threshold)
	Set the threshold level.
Public Member Functions inherited from log4cxx::Appender
virtual	~Appender ()
virtual void	addFilter (const spi::FilterPtr newFilter)=0
	Add a filter to the end of the filter list.
virtual spi::FilterPtr	getFilter () const =0
	Returns the head Filter.
virtual void	clearFilters ()=0
	Clear the list of filters by removing all the filters in it.
virtual void	close ()=0
	Release any resources allocated within the appender such as file handles, network connections, etc.
virtual void	doAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)=0
	Log in Appender specific way.
virtual LogString	getName () const =0
	Get the name of this appender.
virtual void	setLayout (const LayoutPtr layout)=0
	Set the Layout for this appender.
virtual LayoutPtr	getLayout () const =0
	Returns this appenders layout.
virtual void	setName (const LogString &name)=0
	Set the name of this appender.
virtual bool	requiresLayout () const =0
	Configurators call this method to determine if the appender requires a layout.
Public Member Functions inherited from log4cxx::spi::OptionHandler
virtual	~OptionHandler ()
virtual void	activateOptions (helpers::Pool &p)=0
	Activate the options that were previously set with calls to option setters.
virtual void	setOption (const LogString &option, const LogString &value)=0
	Set option to value.
Public Member Functions inherited from log4cxx::helpers::Object
virtual	~Object ()
virtual const helpers::Class &	getClass () const =0
virtual bool	instanceof (const Class &clazz) const =0
virtual const void *	cast (const Class &clazz) const =0

Protected Member Functions
	WriterAppender (const LayoutPtr &layout, helpers::WriterPtr &writer)
	WriterAppender (const LayoutPtr &layout)
	WriterAppender (std::unique_ptr< WriterAppenderPriv > priv)
virtual bool	checkEntryConditions () const
	This method determines if there is a sense in attempting to append.
void	closeWriter ()
	Close the underlying log4cxx::helpers::Writer.
virtual helpers::WriterPtr	createWriter (LOG4CXX_16_CONST helpers::OutputStreamPtr &os)
	Returns an OutputStreamWriter when passed an OutputStream.
virtual void	subAppend (const spi::LoggingEventPtr &event, helpers::Pool &p)
	Actual writing occurs here.
virtual void	writeFooter (helpers::Pool &p)
	Write a footer as produced by the embedded layout's Layout::appendFooter method.
virtual void	writeHeader (helpers::Pool &p)
	Write a header as produced by the embedded layout's Layout::appendHeader method.
void	setWriterInternal (const helpers::WriterPtr &writer)
	Set the writer.
Protected Member Functions inherited from log4cxx::AppenderSkeleton
	AppenderSkeleton (LOG4CXX_PRIVATE_PTR(AppenderSkeletonPrivate) priv)
virtual void	append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)=0
	Subclasses of AppenderSkeleton should implement this method to perform actual logging.
void	doAppendImpl (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)

WriterAppender appends log events to a standard output stream.

This default constructor does nothing.

◆ WriterAppender() [2/4]

◆ WriterAppender() [3/4]

◆ WriterAppender() [4/4]

◆ ~WriterAppender()

◆ activateOptions()

◆ append()

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 log4cxx::AppenderSkeleton.

◆ checkEntryConditions()

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.

◆ close()

Close this appender instance.

The underlying stream or writer is also closed.

Closed appenders cannot be reused.

Implements log4cxx::Appender.

◆ closeWriter()

◆ createWriter()

◆ getEncoding()

The current encoding value.

See also

setOption

◆ getImmediateFlush()

Returns value of the ImmediateFlush option.

◆ getWriter()

◆ requiresLayout()

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 log4cxx::Appender.

◆ setEncoding()

◆ setImmediateFlush()

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.

◆ setOption()

Set option to value.

See also

AppenderSkeleton::setOption()

Reimplemented from log4cxx::AppenderSkeleton.

◆ setWriter()

Send log output to writer which must be open and be writable.

The helpers::Writer will be closed when the appender instance is closed.

WARNING: Logging to an unopened Writer will fail.

Parameters

◆ setWriterInternal()

Set the writer.

Mutex must already be held.

◆ subAppend()

◆ writeFooter()

◆ writeHeader()

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

• writerappender.h