net.sf.eBus.util.logging

Class CalendarFileHandler

java.lang.Object

java.util.logging.Handler

java.util.logging.StreamHandler

net.sf.eBus.util.logging.CalendarFileHandler

All Implemented Interfaces:

TimerTaskListener

public final class CalendarFileHandler
extends StreamHandler
implements TimerTaskListener

Logs messages to a user-specified file, rolling over to a new file at midnight. Log files are kept for only so many days before CalendarFileHandler deletes them. This retention limit is configurable but defaults to 10 days.

The CalendarFileHandler uses three parameters to generate the complete file name:

 <base name>.<date pattern>.<extension>
 

1. Base Name: Store the log files here using this base name.

   Example: /var/log/app/app

2. Date Pattern: Use this pattern to format the date portion of the file name.

   The data pattern is passed to a SimpleDateFormat.SimpleDateFormat(String). See SimpleDateFormat for a detailed explanation of valid date formats.

3. Extension: This is first part of the log file's name.

   Example: log

Given the base name /var/log/eBus/eBus, a date pattern "ddMMyyyy" and extension log, the July 15, 2001 log file name is /var/log/eBus/eBus.15072001.log

Configuration: CalendarFileHandler default configuration uses the following LogManager properties. If the named properties are either not defined or have invalid values, then the default settings are used.

• net.sf.eBus.util.logging.CalendarFileHandler.basename (defaults to "./Logger")
• net.sf.eBus.util.logging.CalendarFileHandler.pattern (defaults to "yyyyMMdd")
• net.sf.eBus.util.logging.CalendarFileHandler.extension (defaults to "log")
• net.sf.eBus.util.logging.CalendarFileHandler.days_kept (defaults to 10 days)
• net.sf.eBus.util.logging.CalendarFileHandler.formatter (defaults to "net.sf.eBus.util.logging.PatternFormatter")
• net.sf.eBus.util.logging.CalendarFileHandler.level (defaults to system default)

Author:

Charles Rapp

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_BASENAME The log file's default base name is "Logger".
static String	DEFAULT_DATE_FORMAT The log file's default data format is "yyyyMMdd".
static int	DEFAULT_DAYS_KEPT Log files are kept for 10 days by default.
static String	DEFAULT_DIRECTORY Log files are placed in the application's current working directory (".") by default.
static String	DEFAULT_EXTENSION The default file extension is "log".
static Level	DEFAULT_LEVEL The log file handler default level is Level.INFO.
static int	MAX_DAYS_KEPT The maximum number of days a log file is kept is 96.
static int	MIN_DAYS_KEPT The minimum number of days a log file is kept is 0 which means that the file is deleted as soon as the day ends.

Constructor Summary

Constructors

Constructor and Description
CalendarFileHandler() Creates a new CalendarFileHandler and configures it according to LogManager configuration properties.
CalendarFileHandler(String baseName, String datePattern, String extension, int daysKept) Creates a new CalendarFileHandler instance for the specified base name, date format pattern, file name extension and how long to keep the files around.

Method Summary

Modifier and Type	Method and Description
void	handleTimeout(TimerEvent task) Time to roll over to the next log file.
void	publish(LogRecord record) Flushes the output stream after StreamHandler publishes the log record.

Methods inherited from class java.util.logging.StreamHandler

close, flush, isLoggable, setEncoding, setOutputStream

Methods inherited from class java.util.logging.Handler

getEncoding, getErrorManager, getFilter, getFormatter, getLevel, reportError, setErrorManager, setFilter, setFormatter, setLevel

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_DIRECTORY

public static final String DEFAULT_DIRECTORY

Log files are placed in the application's current working directory (".") by default.

See Also:

Constant Field Values

DEFAULT_BASENAME

public static final String DEFAULT_BASENAME

The log file's default base name is "Logger".

See Also:

Constant Field Values

DEFAULT_DATE_FORMAT

public static final String DEFAULT_DATE_FORMAT

The log file's default data format is "yyyyMMdd". For July 4, 1776 the formatted string is "17760704".

See Also:

Constant Field Values

DEFAULT_LEVEL

public static final Level DEFAULT_LEVEL

The log file handler default level is Level.INFO.

DEFAULT_EXTENSION

public static final String DEFAULT_EXTENSION

The default file extension is "log".

See Also:

Constant Field Values

MIN_DAYS_KEPT

public static final int MIN_DAYS_KEPT

The minimum number of days a log file is kept is 0 which means that the file is deleted as soon as the day ends.

See Also:

Constant Field Values

MAX_DAYS_KEPT

public static final int MAX_DAYS_KEPT

The maximum number of days a log file is kept is 96. That's three months. That is plenty of time to archive the file if necessary.

See Also:

Constant Field Values

DEFAULT_DAYS_KEPT

public static final int DEFAULT_DAYS_KEPT

Log files are kept for 10 days by default.

See Also:

Constant Field Values

Constructor Detail

CalendarFileHandler

public CalendarFileHandler()
                    throws IOException,
                           ClassNotFoundException,
                           NoSuchMethodException,
                           InstantiationException,
                           IllegalAccessException,
                           InvocationTargetException

Creates a new CalendarFileHandler and configures it according to LogManager configuration properties.

Throws:

IllegalArgumentException - if LogManager configuration properties contains invalid or incorrect settings.

IOException - if defined log directory is invalid.

ClassNotFoundException - if defined formatter is not a known Java class.

NoSuchMethodException - if defined formatter does not have a default constructor defined.

InstantiationException - if defined formatter instantiation failed.

IllegalAccessException - if defined formatter default constructor is inaccessible.

InvocationTargetException - if formatter instantiation failed.

CalendarFileHandler

public CalendarFileHandler(String baseName,
                           String datePattern,
                           String extension,
                           int daysKept)
                    throws IOException,
                           ClassNotFoundException,
                           NoSuchMethodException,
                           InstantiationException,
                           IllegalAccessException,
                           InvocationTargetException

Creates a new CalendarFileHandler instance for the specified base name, date format pattern, file name extension and how long to keep the files around.

Parameters:

baseName - where to put the log files.

datePattern - date format

extension - file name extension

daysKept - how long the log files are kept around (in days).

Throws:

IllegalArgumentException - if:

• if baseName, datePattern or extension is null.
• baseName, datePattern or extension is an empty string.
• daysKept is < MIN_DAYS_KEPT or > MAX_DAYS_KEPT.
• datePattern is an invalid date format pattern as per java.text.SimpleDateFormat.
• baseName is in an unknown directory or directory cannot be accessed.

IllegalArgumentException - if any of the given parameters is set to an invalid value.

IOException - if defined log directory is invalid.

ClassNotFoundException - if defined formatter is not a known Java class.

NoSuchMethodException - if defined formatter does not have a default constructor defined.

InstantiationException - if defined formatter instantiation failed.

IllegalAccessException - if defined formatter default constructor is inaccessible.

InvocationTargetException - if formatter instantiation failed.

Method Detail

handleTimeout

public void handleTimeout(TimerEvent task)

Time to roll over to the next log file.

Specified by:

handleTimeout in interface TimerTaskListener

Parameters:

task - the roll file timer task.

publish

public void publish(LogRecord record)

Flushes the output stream after StreamHandler publishes the log record. StreamHandler does not do this which means records are not seen in the log file as they are published.

Overrides:

publish in class StreamHandler

Parameters:

record - Publish this log record to the log file.