org.ka2ddo.yaac.core

Class FileLogger<T>

java.lang.Object

org.ka2ddo.util.ReschedulableTimerTask

org.ka2ddo.yaac.core.FileLogger<T>

All Implemented Interfaces:

java.lang.Comparable<ReschedulableTimerTask>, java.lang.Runnable, ShutdownHandler

Direct Known Subclasses:

AX25Logger, StringLogger

public abstract class FileLogger<T>
extends ReschedulableTimerTask
implements ShutdownHandler

This class implements a generic time-batched logging facility for an arbitrary record type T in a date-rolled sequential logging file.

Author:

Andrew Pavlin, KA2DDO

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FileLogger.RolloverHandler<T> Define a handler to be called when the logger rolls over to a new file.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FileLogger(java.lang.String prefix, java.lang.String datePattern, java.lang.String suffix, int flushEveryNSeconds) Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in YAAC's default log directory.
protected	FileLogger(java.lang.String prefix, java.lang.String datePattern, java.lang.String suffix, int flushEveryNSeconds, long rolloverInterval) Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in YAAC's default log directory.
protected	FileLogger(java.lang.String prefix, java.lang.String datePattern, java.lang.String suffix, int flushEveryNSeconds, java.lang.String logDirPath) Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in the explicitly specified log directory.

Method Summary

Modifier and Type	Method and Description
abstract void	dumpRecordQueueToFile(java.io.File logFileFile, java.util.ArrayList<T> recordQueue) Subclasses should implement this method to open the specified sequential file for append, then write each of the records in the recordQueue in order to the file, then close the file.
void	flush() Dump the current contents of the backlog queue to the current log file.
static java.io.File	getDefaultLogDir() Get the current default directory used for log files.
void	log(T record) Append one record to the log file, using asynchronous background writing.
void	log(T record, java.util.Date date) Append one record to the log file, using asynchronous background writing.
void	log(T record, long date) Append one record to the log file, using asynchronous background writing.
void	run() DO NOT CALL.
void	setDatePattern(java.lang.String datePattern) Set the pattern for formatting the date stamp in the log file name.
static void	setDefaultLogDir(java.lang.String defaultLogDirPath) Specify the default directory where all log files will be kept.
void	setFilePrefix(java.lang.String prefix) Change the constant prefix that should be used before the date part of the log file name.
void	setFileSuffix(java.lang.String suffix) Change the constant suffix that should be used after the date part of the log file name.
void	setFlushInterval(int flushEveryNSeconds) Set how frequently the logger should dump its backlog queue to disk and close the file for checkpointing.
void	setLogDirectory(java.lang.String logDirPath) Set the directory in which log files should be created.
void	setRolloverHandler(FileLogger.RolloverHandler<T> rolloverHandler) Set (or clear) the handler to be informed whenever the FileLogger advances to a new periodic log file.
void	setRolloverInterval(long rolloverInterval) Set the interval between closing of one log file and opening of the next.
void	setTimeZone(java.util.TimeZone tz) Set the time zone for use in calculating file rollovers.
void	shutdown() Do whatever cleanup this object needs for program shutdown.

Methods inherited from class org.ka2ddo.util.ReschedulableTimerTask

cancel, compareTo, equals, hashCode, isActive, resched, resched, resched, resched

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileLogger

protected FileLogger(java.lang.String prefix,
                     java.lang.String datePattern,
                     java.lang.String suffix,
                     int flushEveryNSeconds)

Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in YAAC's default log directory.

Parameters:

prefix - String file name prefix (before the date)

datePattern - format string for file name embedded date, using SimpleDateFormat directives

suffix - String file name suffix (after the date)

flushEveryNSeconds - the interval between log flushes in seconds

See Also:

setDefaultLogDir(String)

FileLogger

protected FileLogger(java.lang.String prefix,
                     java.lang.String datePattern,
                     java.lang.String suffix,
                     int flushEveryNSeconds,
                     long rolloverInterval)

Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in YAAC's default log directory.

Parameters:

prefix - String file name prefix (before the date)

datePattern - format string for file name embedded date, using SimpleDateFormat directives

suffix - String file name suffix (after the date)

flushEveryNSeconds - the interval between log flushes in seconds

rolloverInterval - the interval in milliseconds between log file changes

See Also:

setDefaultLogDir(String)

FileLogger

protected FileLogger(java.lang.String prefix,
                     java.lang.String datePattern,
                     java.lang.String suffix,
                     int flushEveryNSeconds,
                     java.lang.String logDirPath)

Create a FileLogger using the specified file prefix, date pattern, suffix, and flush interval, storing the log files in the explicitly specified log directory.

Parameters:

prefix - String file name prefix (before the date)

datePattern - format string for file name embedded date, using SimpleDateFormat directives

suffix - String file name suffix (after the date)

flushEveryNSeconds - the interval between log flushes in seconds

logDirPath - String path name of directory to contain the log files

Method Detail

setLogDirectory

public void setLogDirectory(java.lang.String logDirPath)

Set the directory in which log files should be created. If the directory does not exist, this method will attempt to create it.

Parameters:

logDirPath - String pathname of log-containing directory

setDefaultLogDir

public static void setDefaultLogDir(java.lang.String defaultLogDirPath)

Specify the default directory where all log files will be kept.

Parameters:

defaultLogDirPath - String absolute path to a directory

getDefaultLogDir

public static java.io.File getDefaultLogDir()

Get the current default directory used for log files. Note that individual loggers can override this.

Returns:

File of default log directory (null if not set yet)

setFlushInterval

public void setFlushInterval(int flushEveryNSeconds)

Set how frequently the logger should dump its backlog queue to disk and close the file for checkpointing.

Parameters:

flushEveryNSeconds - the interval in seconds between file closes

setTimeZone

public void setTimeZone(java.util.TimeZone tz)

Set the time zone for use in calculating file rollovers. The rollover interval should be whole divisions of a day (up to a full day), and are aligned with the time zone's midnight.

Parameters:

tz - TimeZone to use for calculating rollovers

setRolloverInterval

public void setRolloverInterval(long rolloverInterval)

Set the interval between closing of one log file and opening of the next. Note that these intervals are measured relative to the FileLogger's time zone's midnight, so it is recommended that the chosen value be an integer fraction of 86400000 (the number of milliseconds in a day).

Parameters:

rolloverInterval - time span for each log file instance in milliseconds

setDatePattern

public void setDatePattern(java.lang.String datePattern)

Set the pattern for formatting the date stamp in the log file name. This uses Java SimpleDateFormat formatting, and it is suggested that the user not specify a format with whitespace in it, to prevent command-line issues in dealing with the created files. The user is responsible for specifying a format whose resolution is commensurate with the rollover interval. For example, specifying a rolloverInterval of 1 hour but having a datePattern only showing the date without the hour of day would cause all 24 hours of log files to have the same name.

Parameters:

datePattern - String pattern for generating the date stamp in the file name

See Also:

setRolloverInterval(long)

setFilePrefix

public void setFilePrefix(java.lang.String prefix)

Change the constant prefix that should be used before the date part of the log file name.

Parameters:

prefix - String name prefix

setFileSuffix

public void setFileSuffix(java.lang.String suffix)

Change the constant suffix that should be used after the date part of the log file name.

Parameters:

suffix - String name suffix

log

public void log(T record)

Append one record to the log file, using asynchronous background writing.

Parameters:

record - data record to log of the specified generic type

log

public void log(T record,
                java.util.Date date)

Append one record to the log file, using asynchronous background writing.

Parameters:

record - data record to log of the specified generic type

date - Date when record was created, received, etc.

log

public void log(T record,
                long date)

Append one record to the log file, using asynchronous background writing.

Parameters:

record - data record to log of the specified generic type

date - long timestamp in milliseconds since midnight Jan 19 1970 UTC when record was created, received, etc.

flush

public void flush()

Dump the current contents of the backlog queue to the current log file.

setRolloverHandler

public void setRolloverHandler(FileLogger.RolloverHandler<T> rolloverHandler)

Set (or clear) the handler to be informed whenever the FileLogger advances to a new periodic log file.

Parameters:

rolloverHandler - RolloverHandler instance to be informed of rollovers, or null to no longer be informed

dumpRecordQueueToFile

public abstract void dumpRecordQueueToFile(java.io.File logFileFile,
                                           java.util.ArrayList<T> recordQueue)
                                    throws java.io.IOException

Subclasses should implement this method to open the specified sequential file for append, then write each of the records in the recordQueue in order to the file, then close the file.

Parameters:

logFileFile - File identifying the log file to open and write

recordQueue - the ArrayList of ordered records to write

Throws:

java.io.IOException - if record saving fails for any reason

run

public final void run()

DO NOT CALL. Task for executing periodic flushes of log file.

Specified by:

run in interface java.lang.Runnable

shutdown

public void shutdown()

Do whatever cleanup this object needs for program shutdown.

Specified by:

shutdown in interface ShutdownHandler