maslab.util
Class Logger

java.lang.Object
  maslab.util.Logger

public class Logger
extends java.lang.Object

A simple logging facility designed for all of a program's textual output. Output sources are categorized by "channel names", typically on a per-class basis. Output can be redirected arbitrarily by providing publishers.

Field Summary

static ConsoleLoggerPublisher	consolePublisher
static int	DEBUG extensive debugging information
static int	ERROR failure has occurred, typically fatal
static int	OUTPUT the expected output of the program.
static int	SILENT Used only by LoggerPublishers: indicates that no messages should be published.
static long	startTime
static int	VDEBUG ludicrous quantities of debug information
static int	VERBOSE occasional status messages
static int	VVERBOSE more frequent status messages
static int	WARN a recoverable failure has occurred, or something suspicious occured.

Constructor Summary

Logger(java.lang.Object o)
Create a logger which will take its name as the class name of the argument.

Logger(java.lang.String name)
Create a new logger with the specified name.

Method Summary

static void	addPublisher(LoggerPublisher publisher) Add a new publisher
void	debug(java.lang.String message) A convenience method
void	error(java.lang.String message) A convenience method
void	error(java.lang.String message, java.lang.Exception ex) A convenience method
static java.lang.String	getNameFromObject(java.lang.Object o)
static java.lang.String	levelToString(int level) Convert an integer value corresponding to a debug level into a human-readable string, e.g.
void	log(int level, java.lang.String message) Log a message for this channel
void	log(int level, java.lang.String message, java.lang.Exception ex) Log a message for this channel
static void	log(java.lang.String name, int level, java.lang.String message) The actual log method.
static void	log(java.lang.String name, int level, java.lang.String message, java.lang.Exception ex) Produce a log message containing information about an exception that occured.
static void	main(java.lang.String[] args)
void	output(java.lang.String message) A convenience method
void	output(java.lang.String message, java.lang.Exception ex) A convenience method
static void	removePublisher(LoggerPublisher publisher) Remove a publisher that has previously been added.
void	vdebug(java.lang.String message) A convenience method
void	verbose(java.lang.String message) A convenience method
void	vverbose(java.lang.String message) A convenience method
void	warn(java.lang.String message) A convenience method
void	warn(java.lang.String message, java.lang.Exception ex) A convenience method

Methods inherited from class java.lang.Object

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

Field Detail

SILENT

public static final int SILENT

Used only by LoggerPublishers: indicates that no messages should be published. You should not publish messages at this priority.

See Also:

Constant Field Values

ERROR

public static final int ERROR

failure has occurred, typically fatal

See Also:

Constant Field Values

WARN

public static final int WARN

a recoverable failure has occurred, or something suspicious occured.

See Also:

Constant Field Values

OUTPUT

public static final int OUTPUT

the expected output of the program.

See Also:

Constant Field Values

VERBOSE

public static final int VERBOSE

occasional status messages

See Also:

Constant Field Values

VVERBOSE

public static final int VVERBOSE

more frequent status messages

See Also:

Constant Field Values

DEBUG

public static final int DEBUG

extensive debugging information

See Also:

Constant Field Values

VDEBUG

public static final int VDEBUG

ludicrous quantities of debug information

See Also:

Constant Field Values

consolePublisher

public static ConsoleLoggerPublisher consolePublisher

startTime

public static long startTime

Constructor Detail

Logger

public Logger(java.lang.String name)

Create a new logger with the specified name.

Logger

public Logger(java.lang.Object o)

Create a logger which will take its name as the class name of the argument.

Method Detail

levelToString

public static java.lang.String levelToString(int level)

Convert an integer value corresponding to a debug level into a human-readable string, e.g. "VERBOSE".

Parameters:

level - One of the static levels provided by this class.

Returns:

a human-readable string, e.g. "VERBOSE".

getNameFromObject

public static java.lang.String getNameFromObject(java.lang.Object o)

log

public void log(int level,
                java.lang.String message)

Log a message for this channel

log

public void log(int level,
                java.lang.String message,
                java.lang.Exception ex)

Log a message for this channel

error

public void error(java.lang.String message,
                  java.lang.Exception ex)

A convenience method

error

public void error(java.lang.String message)

A convenience method

warn

public void warn(java.lang.String message,
                 java.lang.Exception ex)

A convenience method

warn

public void warn(java.lang.String message)

A convenience method

output

public void output(java.lang.String message)

A convenience method

output

public void output(java.lang.String message,
                   java.lang.Exception ex)

A convenience method

verbose

public void verbose(java.lang.String message)

A convenience method

vverbose

public void vverbose(java.lang.String message)

A convenience method

debug

public void debug(java.lang.String message)

A convenience method

vdebug

public void vdebug(java.lang.String message)

A convenience method

addPublisher

public static void addPublisher(LoggerPublisher publisher)

Add a new publisher

Parameters:

publisher - a new LoggerPublisher which will be told about all events.

removePublisher

public static void removePublisher(LoggerPublisher publisher)

Remove a publisher that has previously been added.

Parameters:

publisher - The publisher to be removed.

log

public static void log(java.lang.String name,
                       int level,
                       java.lang.String message,
                       java.lang.Exception ex)

Produce a log message containing information about an exception that occured. Many of the convenience methods ultimately call this function. The convenience methods should typically be used for readability.

log

public static void log(java.lang.String name,
                       int level,
                       java.lang.String message)

The actual log method. All other log calls ultimately call this method which actually invokes the publishers.

Parameters:

name - The channel name

level - The log level

message - The message

main

public static void main(java.lang.String[] args)