log4cxx::WriterAppender

WriterAppender Class Reference

Inherits AppenderSkeleton.

Inherited by ConsoleAppender, and FileAppender.

List of all members.

Detailed Description

WriterAppender appends log events to a standard output stream.


Public Member Functions

 WriterAppender ()
 This default constructor does nothing.
 ~WriterAppender ()
virtual void activateOptions (log4cxx::helpers::Pool &pool)
 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.
virtual void append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)
 This method is called by the AppenderSkeleton::doAppend method.
virtual void close ()
 Close this appender instance.
LogString getEncoding () const
void setEncoding (const LogString &value)
void setOption (const LogString &option, const LogString &value)
 Set option to value.
void setWriter (const log4cxx::helpers::WriterPtr &writer)
virtual bool requiresLayout () const
 Configurators call this method to determine if the appender requires a layout.

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.
void closeWriter ()
 Close the underlying log4cxx::helpers::Writer.
virtual log4cxx::helpers::WriterPtr createWriter (log4cxx::helpers::OutputStreamPtr &os)
 Returns an OutputStreamWriter when passed an OutputStream.
virtual void subAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)
 Actual writing occurs here.
virtual void writeFooter (log4cxx::helpers::Pool &p)
 Write a footer as produced by the embedded layout's Layout::appendFooter method.
virtual void writeHeader (log4cxx::helpers::Pool &p)
 Write a header as produced by the embedded layout's Layout::appendHeader method.

Constructor & Destructor Documentation

WriterAppender (   ) 
 

This default constructor does nothing.

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

WriterAppender (  const LayoutPtr &  layout  )  [protected]
 

~WriterAppender (   ) 
 

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 ConsoleAppender, DailyRollingFileAppender, FileAppender, RollingFileAppenderSkeleton, and RollingFileAppender.

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 [protected, virtual]
 

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  )  [protected, virtual]
 

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.

Reimplemented in ConsoleAppender, DailyRollingFileAppender, FileAppender, and RollingFileAppender.

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:
writer An already opened Writer.

virtual void subAppend (  const spi::LoggingEventPtr &  event,
log4cxx::helpers::Pool &  p
)  [protected, virtual]
 

Actual writing occurs here.

Reimplemented in RollingFileAppenderSkeleton.

virtual void writeFooter (  log4cxx::helpers::Pool &  p  )  [protected, virtual]
 

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

virtual void writeHeader (  log4cxx::helpers::Pool &  p  )  [protected, virtual]
 

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

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