org.slf4j.impl

Class SimpleLogger

java.lang.Object

org.slf4j.helpers.MarkerIgnoringBase

org.slf4j.impl.SimpleLogger

All Implemented Interfaces:

Serializable, Logger

public class SimpleLogger
extends MarkerIgnoringBase

Simple implementation of Logger that sends all enabled log messages, for all defined loggers, to the console (System.err). The following system properties are supported to configure the behavior of this logger:

• org.slf4j.simpleLogger.logFile - The output target which can be the path to a file, or the special values "System.out" and "System.err". Default is "System.err".
• org.slf4j.simpleLogger.defaultLogLevel - Default log level for all instances of SimpleLogger. Must be one of ("trace", "debug", "info", "warn", or "error"). If not specified, defaults to "info".
• org.slf4j.simpleLogger.log.a.b.c - Logging detail level for a SimpleLogger instance named "a.b.c". Right-side value must be one of "trace", "debug", "info", "warn", or "error". When a SimpleLogger named "a.b.c" is initialized, its level is assigned from this property. If unspecified, the level of nearest parent logger will be used, and if none is set, then the value specified by org.slf4j.simpleLogger.defaultLogLevel will be used.
• org.slf4j.simpleLogger.showDateTime - Set to true if you want the current date and time to be included in output messages. Default is false
• org.slf4j.simpleLogger.dateTimeFormat - The date and time format to be used in the output messages. The pattern describing the date and time format is defined by SimpleDateFormat. If the format is not specified or is invalid, the number of milliseconds since start up will be output.
• org.slf4j.simpleLogger.showThreadName -Set to true if you want to output the current thread name. Defaults to true.
• org.slf4j.simpleLogger.showLogName - Set to true if you want the Logger instance name to be included in output messages. Defaults to true.
• org.slf4j.simpleLogger.showShortLogName - Set to true if you want the last component of the name to be included in output messages. Defaults to false.
• org.slf4j.simpleLogger.levelInBrackets - Should the level string be output in brackets? Defaults to false.
• org.slf4j.simpleLogger.warnLevelString - The string value output for the warn level. Defaults to WARN.

In addition to looking for system properties with the names specified above, this implementation also checks for a class loader resource named "simplelogger.properties", and includes any matching definitions from this resource (if it exists).

With no configuration, the default output includes the relative time in milliseconds, thread name, the level, logger name, and the message followed by the line separator for the host. In log4j terms it amounts to the "%r [%t] %level %logger - %m%n" pattern.

Sample output follows.

 176 [main] INFO examples.Sort - Populating an array of 2 elements in reverse order.
 225 [main] INFO examples.SortAlgo - Entered the sort method.
 304 [main] INFO examples.SortAlgo - Dump of integer array:
 317 [main] INFO examples.SortAlgo - Element [0] = 0
 331 [main] INFO examples.SortAlgo - Element [1] = 1
 343 [main] INFO examples.Sort - The next log statement should be an error message.
 346 [main] ERROR examples.SortAlgo - Tried to dump an uninitialized array.
   at org.log4j.examples.SortAlgo.dump(SortAlgo.java:58)
   at org.log4j.examples.Sort.main(Sort.java:64)
 467 [main] INFO  examples.Sort - Exiting main method.
 

This implementation is heavily inspired by Apache Commons Logging's SimpleLog.

Author:

Ceki Gülcü, Scott Sanders, Rod Waldhoff, Robert Burrell Donkin, Cédrik LIME

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	currentLogLevel The current log level
static String	DATE_TIME_FORMAT_KEY
static String	DEFAULT_LOG_LEVEL_KEY
static String	LEVEL_IN_BRACKETS_KEY
static String	LOG_FILE_KEY
static String	LOG_KEY_PREFIX
protected String	name
static String	SHOW_DATE_TIME_KEY
static String	SHOW_LOG_NAME_KEY
static String	SHOW_SHORT_LOG_NAME_KEY
static String	SHOW_THREAD_NAME_KEY
static String	SYSTEM_PREFIX All system properties used by SimpleLogger start with this prefix
static String	WARN_LEVEL_STRING_KEY

Fields inherited from interface org.slf4j.Logger

ROOT_LOGGER_NAME

Method Summary

Modifier and Type	Method and Description
void	debug(String msg) A simple implementation which logs messages of level DEBUG according to the format outlined above.
void	debug(String format, Object... argArray) Perform double parameter substitution before logging the message of level DEBUG according to the format outlined above.
void	debug(String format, Object param1) Perform single parameter substitution before logging the message of level DEBUG according to the format outlined above.
void	debug(String format, Object param1, Object param2) Perform double parameter substitution before logging the message of level DEBUG according to the format outlined above.
void	debug(String msg, Throwable t) Log a message of level DEBUG, including an exception.
void	error(String msg) A simple implementation which always logs messages of level ERROR according to the format outlined above.
void	error(String format, Object... argArray) Perform double parameter substitution before logging the message of level ERROR according to the format outlined above.
void	error(String format, Object arg) Perform single parameter substitution before logging the message of level ERROR according to the format outlined above.
void	error(String format, Object arg1, Object arg2) Perform double parameter substitution before logging the message of level ERROR according to the format outlined above.
void	error(String msg, Throwable t) Log a message of level ERROR, including an exception.
String	getName() Return the name of this Logger instance.
void	info(String msg) A simple implementation which logs messages of level INFO according to the format outlined above.
void	info(String format, Object... argArray) Perform double parameter substitution before logging the message of level INFO according to the format outlined above.
void	info(String format, Object arg) Perform single parameter substitution before logging the message of level INFO according to the format outlined above.
void	info(String format, Object arg1, Object arg2) Perform double parameter substitution before logging the message of level INFO according to the format outlined above.
void	info(String msg, Throwable t) Log a message of level INFO, including an exception.
boolean	isDebugEnabled() Are debug messages currently enabled?
boolean	isErrorEnabled() Are error messages currently enabled?
boolean	isInfoEnabled() Are info messages currently enabled?
protected boolean	isLevelEnabled(int logLevel) Is the given log level currently enabled?
boolean	isTraceEnabled() Are trace messages currently enabled?
boolean	isWarnEnabled() Are warn messages currently enabled?
protected Object	readResolve() Replace this instance with a homonymous (same name) logger returned by LoggerFactory.
void	trace(String msg) A simple implementation which logs messages of level TRACE according to the format outlined above.
void	trace(String format, Object... argArray) Perform double parameter substitution before logging the message of level TRACE according to the format outlined above.
void	trace(String format, Object param1) Perform single parameter substitution before logging the message of level TRACE according to the format outlined above.
void	trace(String format, Object param1, Object param2) Perform double parameter substitution before logging the message of level TRACE according to the format outlined above.
void	trace(String msg, Throwable t) Log a message of level TRACE, including an exception.
void	warn(String msg) A simple implementation which always logs messages of level WARN according to the format outlined above.
void	warn(String format, Object... argArray) Perform double parameter substitution before logging the message of level WARN according to the format outlined above.
void	warn(String format, Object arg) Perform single parameter substitution before logging the message of level WARN according to the format outlined above.
void	warn(String format, Object arg1, Object arg2) Perform double parameter substitution before logging the message of level WARN according to the format outlined above.
void	warn(String msg, Throwable t) Log a message of level WARN, including an exception.

Methods inherited from class org.slf4j.helpers.MarkerIgnoringBase

debug, debug, debug, debug, debug, error, error, error, error, error, info, info, info, info, info, isDebugEnabled, isErrorEnabled, isInfoEnabled, isTraceEnabled, isWarnEnabled, toString, trace, trace, trace, trace, trace, warn, warn, warn, warn, warn

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.slf4j.Logger

getName

Field Detail

SYSTEM_PREFIX

public static final String SYSTEM_PREFIX

All system properties used by SimpleLogger start with this prefix

See Also:

Constant Field Values

DEFAULT_LOG_LEVEL_KEY

public static final String DEFAULT_LOG_LEVEL_KEY

See Also:

Constant Field Values

SHOW_DATE_TIME_KEY

public static final String SHOW_DATE_TIME_KEY

See Also:

Constant Field Values

DATE_TIME_FORMAT_KEY

public static final String DATE_TIME_FORMAT_KEY

See Also:

Constant Field Values

SHOW_THREAD_NAME_KEY

public static final String SHOW_THREAD_NAME_KEY

See Also:

Constant Field Values

SHOW_LOG_NAME_KEY

public static final String SHOW_LOG_NAME_KEY

See Also:

Constant Field Values

SHOW_SHORT_LOG_NAME_KEY

public static final String SHOW_SHORT_LOG_NAME_KEY

See Also:

Constant Field Values

LOG_FILE_KEY

public static final String LOG_FILE_KEY

See Also:

Constant Field Values

LEVEL_IN_BRACKETS_KEY

public static final String LEVEL_IN_BRACKETS_KEY

See Also:

Constant Field Values

WARN_LEVEL_STRING_KEY

public static final String WARN_LEVEL_STRING_KEY

See Also:

Constant Field Values

LOG_KEY_PREFIX

public static final String LOG_KEY_PREFIX

See Also:

Constant Field Values

currentLogLevel

protected int currentLogLevel

The current log level

name

protected String name

Method Detail

isLevelEnabled

protected boolean isLevelEnabled(int logLevel)

Is the given log level currently enabled?

Parameters:

logLevel - is this level enabled?

isTraceEnabled

public boolean isTraceEnabled()

Are trace messages currently enabled?

Returns:

True if this Logger is enabled for the TRACE level, false otherwise.

trace

public void trace(String msg)

A simple implementation which logs messages of level TRACE according to the format outlined above.

Parameters:

msg - the message string to be logged

trace

public void trace(String format,
                  Object param1)

Perform single parameter substitution before logging the message of level TRACE according to the format outlined above.

Parameters:

format - the format string

param1 - the argument

trace

public void trace(String format,
                  Object param1,
                  Object param2)

Perform double parameter substitution before logging the message of level TRACE according to the format outlined above.

Parameters:

format - the format string

param1 - the first argument

param2 - the second argument

trace

public void trace(String format,
                  Object... argArray)

Perform double parameter substitution before logging the message of level TRACE according to the format outlined above.

Parameters:

format - the format string

argArray - a list of 3 or more arguments

trace

public void trace(String msg,
                  Throwable t)

Log a message of level TRACE, including an exception.

Parameters:

msg - the message accompanying the exception

t - the exception (throwable) to log

isDebugEnabled

public boolean isDebugEnabled()

Are debug messages currently enabled?

Returns:

True if this Logger is enabled for the DEBUG level, false otherwise.

debug

public void debug(String msg)

A simple implementation which logs messages of level DEBUG according to the format outlined above.

Parameters:

msg - the message string to be logged

debug

public void debug(String format,
                  Object param1)

Perform single parameter substitution before logging the message of level DEBUG according to the format outlined above.

Parameters:

format - the format string

param1 - the argument

debug

public void debug(String format,
                  Object param1,
                  Object param2)

Perform double parameter substitution before logging the message of level DEBUG according to the format outlined above.

Parameters:

format - the format string

param1 - the first argument

param2 - the second argument

debug

public void debug(String format,
                  Object... argArray)

Perform double parameter substitution before logging the message of level DEBUG according to the format outlined above.

Parameters:

format - the format string

argArray - a list of 3 or more arguments

debug

public void debug(String msg,
                  Throwable t)

Log a message of level DEBUG, including an exception.

Parameters:

msg - the message accompanying the exception

t - the exception (throwable) to log

isInfoEnabled

public boolean isInfoEnabled()

Are info messages currently enabled?

Returns:

True if this Logger is enabled for the INFO level, false otherwise.

info

public void info(String msg)

A simple implementation which logs messages of level INFO according to the format outlined above.

Parameters:

msg - the message string to be logged

info

public void info(String format,
                 Object arg)

Perform single parameter substitution before logging the message of level INFO according to the format outlined above.

Parameters:

format - the format string

arg - the argument

info

public void info(String format,
                 Object arg1,
                 Object arg2)

Perform double parameter substitution before logging the message of level INFO according to the format outlined above.

Parameters:

format - the format string

arg1 - the first argument

arg2 - the second argument

info

public void info(String format,
                 Object... argArray)

Perform double parameter substitution before logging the message of level INFO according to the format outlined above.

Parameters:

format - the format string

argArray - a list of 3 or more arguments

info

public void info(String msg,
                 Throwable t)

Log a message of level INFO, including an exception.

Parameters:

msg - the message accompanying the exception

t - the exception (throwable) to log

isWarnEnabled

public boolean isWarnEnabled()

Are warn messages currently enabled?

Returns:

True if this Logger is enabled for the WARN level, false otherwise.

warn

public void warn(String msg)

A simple implementation which always logs messages of level WARN according to the format outlined above.

Parameters:

msg - the message string to be logged

warn

public void warn(String format,
                 Object arg)

Perform single parameter substitution before logging the message of level WARN according to the format outlined above.

Parameters:

format - the format string

arg - the argument

warn

public void warn(String format,
                 Object arg1,
                 Object arg2)

Perform double parameter substitution before logging the message of level WARN according to the format outlined above.

Parameters:

format - the format string

arg1 - the first argument

arg2 - the second argument

warn

public void warn(String format,
                 Object... argArray)

Perform double parameter substitution before logging the message of level WARN according to the format outlined above.

Parameters:

format - the format string

argArray - a list of 3 or more arguments

warn

public void warn(String msg,
                 Throwable t)

Log a message of level WARN, including an exception.

Parameters:

msg - the message accompanying the exception

t - the exception (throwable) to log

isErrorEnabled

public boolean isErrorEnabled()

Are error messages currently enabled?

Returns:

True if this Logger is enabled for the ERROR level, false otherwise.

error

public void error(String msg)

A simple implementation which always logs messages of level ERROR according to the format outlined above.

Parameters:

msg - the message string to be logged

error

public void error(String format,
                  Object arg)

Perform single parameter substitution before logging the message of level ERROR according to the format outlined above.

Parameters:

format - the format string

arg - the argument

error

public void error(String format,
                  Object arg1,
                  Object arg2)

Perform double parameter substitution before logging the message of level ERROR according to the format outlined above.

Parameters:

format - the format string

arg1 - the first argument

arg2 - the second argument

error

public void error(String format,
                  Object... argArray)

Perform double parameter substitution before logging the message of level ERROR according to the format outlined above.

Parameters:

format - the format string

argArray - a list of 3 or more arguments

error

public void error(String msg,
                  Throwable t)

Log a message of level ERROR, including an exception.

Parameters:

msg - the message accompanying the exception

t - the exception (throwable) to log

getName

public String getName()

Description copied from interface: Logger

Return the name of this Logger instance.

Specified by:

getName in interface Logger

Returns:

name of this logger instance

readResolve

protected Object readResolve()
                      throws ObjectStreamException

Replace this instance with a homonymous (same name) logger returned by LoggerFactory. Note that this method is only called during deserialization.

This approach will work well if the desired ILoggerFactory is the one references by LoggerFactory. However, if the user manages its logger hierarchy through a different (non-static) mechanism, e.g. dependency injection, then this approach would be mostly counterproductive.

Returns:

logger with same name as returned by LoggerFactory

Throws:

ObjectStreamException