public class

FileAppender

extends WriterAppender

java.lang.Object
↳	org.apache.log4j.AppenderSkeleton
	↳	org.apache.log4j.WriterAppender
		↳	org.apache.log4j.FileAppender

Known Direct Subclasses

DailyRollingFileAppender, RollingFileAppender

Known Indirect Subclasses

ExternallyRolledFileAppender

Class Overview

FileAppender appends log events to a file.

Support for java.io.Writer and console appending has been deprecated and then removed. See the replacement solutions: WriterAppender and ConsoleAppender.

Summary

Fields
protected int	bufferSize	Determines the size of IO buffer be.
protected boolean	bufferedIO	Do we do bufferedIO?
protected boolean	fileAppend	Controls file truncatation.
protected String	fileName	The name of the log file.

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Inherited Fields

From class org.apache.log4j.WriterAppender

From class org.apache.log4j.AppenderSkeleton

Public Constructors
	FileAppender() The default constructor does not do anything.
	FileAppender(Layout layout, String filename, boolean append, boolean bufferedIO, int bufferSize) Instantiate a `FileAppender` and open the file designated by `filename`.
	FileAppender(Layout layout, String filename, boolean append) Instantiate a FileAppender and open the file designated by `filename`.
	FileAppender(Layout layout, String filename) Instantiate a FileAppender and open the file designated by `filename`.

Public Methods
void	activateOptions() If the value of File is not `null`, then `setFile(String)` is called with the values of File and Append properties.
boolean	getAppend() Returns the value of the Append option.
int	getBufferSize() Get the size of the IO buffer.
boolean	getBufferedIO() Get the value of the BufferedIO option.
String	getFile() Returns the value of the File option.
void	setAppend(boolean flag) The Append option takes a boolean value.
void	setBufferSize(int bufferSize) Set the size of the IO buffer.
void	setBufferedIO(boolean bufferedIO) The BufferedIO option takes a boolean value.
void	setFile(String file) The File property takes a string value which should be the name of the file to append to.
synchronized void	setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize) Sets and opens the file where the log output will go.

Protected Methods
void	closeFile() Closes the previously opened file.
void	reset() Close any previously opened file and call the parent's `reset`.
void	setQWForFiles(Writer writer) Sets the quiet writer being used.

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Inherited Methods

From class org.apache.log4j.WriterAppender

void	activateOptions() Does nothing.
void	append(LoggingEvent event) This method is called by the `doAppend(LoggingEvent)` method.
boolean	checkEntryConditions() This method determines if there is a sense in attempting to append.
synchronized void	close() Close this appender instance.
void	closeWriter() Close the underlying java.io.Writer.
OutputStreamWriter	createWriter(OutputStream os) Returns an OutputStreamWriter when passed an OutputStream.
String	getEncoding()
boolean	getImmediateFlush() Returns value of the ImmediateFlush option.
boolean	requiresLayout() The WriterAppender requires a layout.
void	reset() Clear internal references to the writer and other variables.
void	setEncoding(String value)
synchronized void	setErrorHandler(ErrorHandler eh) Set the `ErrorHandler` for this WriterAppender and also the underlying `QuietWriter` if any.
void	setImmediateFlush(boolean value) If the ImmediateFlush option is set to `true`, the appender will flush at the end of each write.
synchronized void	setWriter(Writer writer) Sets the Writer where the log output will go.
boolean	shouldFlush(LoggingEvent event) Determines whether the writer should be flushed after this event is written.
void	subAppend(LoggingEvent event) Actual writing occurs here.
void	writeFooter() Write a footer as produced by the embedded layout's `getFooter()` method.
void	writeHeader() Write a header as produced by the embedded layout's `getHeader()` method.

From class org.apache.log4j.AppenderSkeleton

void	activateOptions() Derived appenders should override this method if option structure requires it.
void	addFilter(Filter newFilter) Add a filter to end of the filter list.
abstract void	append(LoggingEvent event) Subclasses of `AppenderSkeleton` should implement this method to perform actual logging.
void	clearFilters() Clear the filters chain.
synchronized void	doAppend(LoggingEvent event) This method performs threshold checks and invokes filters before delegating actual logging to the subclasses specific `append(LoggingEvent)` method.
void	finalize() Finalize this appender by calling the derived class' `close` method.
ErrorHandler	getErrorHandler() Return the currently set `ErrorHandler` for this Appender.
Filter	getFilter() Returns the head Filter.
final Filter	getFirstFilter() Return the first filter in the filter chain for this Appender.
Layout	getLayout() Returns the layout of this appender.
final String	getName() Returns the name of this appender.
Priority	getThreshold() Returns this appenders threshold level.
boolean	isAsSevereAsThreshold(Priority priority) Check whether the message level is below the appender's threshold.
synchronized void	setErrorHandler(ErrorHandler eh) Set the `ErrorHandler` for this Appender.
void	setLayout(Layout layout) Set the layout for this appender.
void	setName(String name) Set the name of this Appender.
void	setThreshold(Priority threshold) Set the threshold level.

From class java.lang.Object

From interface org.apache.log4j.Appender

abstract void	addFilter(Filter newFilter) Add a filter to the end of the filter list.
abstract void	clearFilters() Clear the list of filters by removing all the filters in it.
abstract void	close() Release any resources allocated within the appender such as file handles, network connections, etc.
abstract void	doAppend(LoggingEvent event) Log in `Appender` specific way.
abstract ErrorHandler	getErrorHandler() Returns the `ErrorHandler` for this appender.
abstract Filter	getFilter() Returns the head Filter.
abstract Layout	getLayout() Returns this appenders layout.
abstract String	getName() Get the name of this appender.
abstract boolean	requiresLayout() Configurators call this method to determine if the appender requires a layout.
abstract void	setErrorHandler(ErrorHandler errorHandler) Set the `ErrorHandler` for this appender.
abstract void	setLayout(Layout layout) Set the `Layout` for this appender.
abstract void	setName(String name) Set the name of this appender.

From interface org.apache.log4j.spi.OptionHandler

Fields

protected int bufferSize

Determines the size of IO buffer be. Default is 8K.

protected boolean bufferedIO

Do we do bufferedIO?

protected boolean fileAppend

Controls file truncatation. The default value for this variable is true, meaning that by default a FileAppender will append to an existing file and not truncate it.

This option is meaningful only if the FileAppender opens the file.

protected String fileName

The name of the log file.

Public Constructors

public FileAppender ()

The default constructor does not do anything.

public FileAppender (Layout layout, String filename, boolean append, boolean bufferedIO, int bufferSize)

Instantiate a FileAppender and open the file designated by filename. The opened filename will become the output destination for this appender.

If the append parameter is true, the file will be appended to. Otherwise, the file designated by filename will be truncated before being opened.

If the bufferedIO parameter is true, then buffered IO will be used to write to the output file.

Throws

IOException

public FileAppender (Layout layout, String filename, boolean append)

Instantiate a FileAppender and open the file designated by filename. The opened filename will become the output destination for this appender.

If the append parameter is true, the file will be appended to. Otherwise, the file designated by filename will be truncated before being opened.

Throws

IOException

public FileAppender (Layout layout, String filename)

Instantiate a FileAppender and open the file designated by filename. The opened filename will become the output destination for this appender.

The file will be appended to.

Throws

IOException

Public Methods

public void activateOptions ()

If the value of File is not null, then setFile(String) is called with the values of File and Append properties.

public boolean getAppend ()

Returns the value of the Append option.

public int getBufferSize ()

Get the size of the IO buffer.

public boolean getBufferedIO ()

Get the value of the BufferedIO option.

BufferedIO will significatnly increase performance on heavily loaded systems.

public String getFile ()

Returns the value of the File option.

public void setAppend (boolean flag)

The Append option takes a boolean value. It is set to true by default. If true, then File will be opened in append mode by setFile (see above). Otherwise, setFile will open File in truncate mode.

Note: Actual opening of the file is made when activateOptions() is called, not when the options are set.

public void setBufferSize (int bufferSize)

Set the size of the IO buffer.

public void setBufferedIO (boolean bufferedIO)

The BufferedIO option takes a boolean value. It is set to false by default. If true, then File will be opened and the resulting java.io.Writer wrapped around a BufferedWriter. BufferedIO will significatnly increase performance on heavily loaded systems.

public void setFile (String file)

The File property takes a string value which should be the name of the file to append to.

Note that the special values "System.out" or "System.err" are no longer honored.

Note: Actual opening of the file is made when activateOptions() is called, not when the options are set.

public synchronized void setFile (String fileName, boolean append, boolean bufferedIO, int bufferSize)

Sets and opens the file where the log output will go. The specified file must be writable.

If there was already an opened file, then the previous file is closed first.

Do not use this method directly. To configure a FileAppender or one of its subclasses, set its properties one by one and then call activateOptions.

Parameters

fileName	The path to the log file.
append	If true will append to fileName. Otherwise will truncate fileName.

Throws

IOException

Protected Methods

protected void closeFile ()

Closes the previously opened file.

protected void reset ()

Close any previously opened file and call the parent's reset.

protected void setQWForFiles (Writer writer)

Sets the quiet writer being used. This method is overriden by RollingFileAppender.

Interfaces

Classes

FileAppender

Class Overview

Summary

Fields

protected int bufferSize

protected boolean bufferedIO

protected boolean fileAppend

protected String fileName

Public Constructors

public FileAppender ()

public FileAppender (Layout layout, String filename, boolean append, boolean bufferedIO, int bufferSize)

Throws

public FileAppender (Layout layout, String filename, boolean append)

Throws

public FileAppender (Layout layout, String filename)

Throws

Public Methods

public void activateOptions ()

public boolean getAppend ()

public int getBufferSize ()

public boolean getBufferedIO ()

public String getFile ()

public void setAppend (boolean flag)

public void setBufferSize (int bufferSize)

public void setBufferedIO (boolean bufferedIO)

public void setFile (String file)

public synchronized void setFile (String fileName, boolean append, boolean bufferedIO, int bufferSize)

Parameters

Throws

Protected Methods

protected void closeFile ()

protected void reset ()

protected void setQWForFiles (Writer writer)