DailyRollingFileAppender

Class Overview

DailyRollingFileAppender extends FileAppender so that the underlying file is rolled over at a user chosen frequency. DailyRollingFileAppender has been observed to exhibit synchronization issues and data loss. The log4j extras companion includes alternatives which should be considered for new deployments and which are discussed in the documentation for org.apache.log4j.rolling.RollingFileAppender.

The rolling schedule is specified by the DatePattern option. This pattern should follow the SimpleDateFormat conventions. In particular, you must escape literal text within a pair of single quotes. A formatted version of the date pattern is used as the suffix for the rolled file name.

For example, if the File option is set to /foo/bar.log and the DatePattern set to '.'yyyy-MM-dd, on 2001-02-16 at midnight, the logging file /foo/bar.log will be copied to /foo/bar.log.2001-02-16 and logging for 2001-02-17 will continue in /foo/bar.log until it rolls over the next day.

Is is possible to specify monthly, weekly, half-daily, daily, hourly, or minutely rollover schedules.

Do not use the colon ":" character in anywhere in the DatePattern option. The text before the colon is interpeted as the protocol specificaion of a URL which is probably not what you want.

Summary

[Expand] Inherited Fields
From class org.apache.log4j.FileAppender 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.
From class org.apache.log4j.WriterAppender protected String encoding The encoding to use when writing. protected boolean immediateFlush Immediate flush means that the underlying writer or output stream will be flushed at the end of each append operation unless shouldFlush() is overridden. protected QuietWriter qw This is the quietWriter where we will write to.
From class org.apache.log4j.AppenderSkeleton protected boolean closed Is this appender closed? protected ErrorHandler errorHandler It is assumed and enforced that errorHandler is never null. protected Filter headFilter The first filter in the filter chain. protected Layout layout The layout variable does not need to be set if the appender implementation has its own layout. protected String name Appenders are named. protected Filter tailFilter The last filter in the filter chain. protected Priority threshold There is no level threshold filtering by default.

[Expand] Inherited Methods
From class org.apache.log4j.FileAppender void activateOptions() If the value of File is not null, then setFile(String) is called with the values of File and Append properties. void closeFile() Closes the previously opened file. 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 reset() Close any previously opened file and call the parent's reset. 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. void setQWForFiles(Writer writer) Sets the quiet writer being used.
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 Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait() final void wait(long arg0, int arg1) final void wait(long arg0)
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 abstract void activateOptions() Activate the options that were previously set with calls to option setters.