Package org.slf4j.impl

Class SimpleLogger

java.lang.Object
org.slf4j.helpers.MarkerIgnoringBase
org.slf4j.impl.SimpleLogger
All Implemented Interfaces:
Serializable, org.slf4j.Logger
Direct Known Subclasses:
MavenSimpleLogger
public class SimpleLogger extends org.slf4j.helpers.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.cacheOutputStream - If the output target is set to "System.out" or "System.err" (see preceding entry), by default, logs will be output to the latest value referenced by System.out/err variables. By setting this parameter to true, the output stream will be cached, i.e. assigned once at initialization time and re-used independently of the current value referenced by System.out/err.
  • org.slf4j.simpleLogger.defaultLogLevel - Default log level for all instances of SimpleLogger. Must be one of "trace", "debug", "info", "warn", "error" or "off". If not specified, defaults to "info".
  • org.slf4j.simpleLogger.log.com.foo.bar - Logging detail level for a SimpleLogger instance named "com.foo.bar". Right-side value must be one of "trace", "debug", "info", "warn", "error" or "off". 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 - If you would like the current date and time to be included in output messages, then set it to true. 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 - If you want to output the current thread name, then set it to true. Defaults to true.
  • (since version 1.7.33 and 2.0.0-alpha6) org.slf4j.simpleLogger.showThreadId - If you would like to output the current thread id, then set to true. Defaults to false.
  • org.slf4j.simpleLogger.showLogName - If you would like the Logger instance name to be included in output messages, then set it to true. 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:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    CACHE_OUTPUT_STREAM_STRING_KEY
     
    protected int
    currentLogLevel
    The current log level
    static final String
    DATE_TIME_FORMAT_KEY
     
    static final String
    DEFAULT_LOG_LEVEL_KEY
     
    static final String
    LEVEL_IN_BRACKETS_KEY
     
    static final String
    LOG_FILE_KEY
     
    static final String
    LOG_KEY_PREFIX
     
    protected static final int
    LOG_LEVEL_DEBUG
     
    protected static final int
    LOG_LEVEL_ERROR
     
    protected static final int
    LOG_LEVEL_INFO
     
    protected static final int
    LOG_LEVEL_OFF
     
    protected static final int
    LOG_LEVEL_TRACE
     
    protected static final int
    LOG_LEVEL_WARN
     
    protected String
    name
     
    static final String
    SHOW_DATE_TIME_KEY
     
    static final String
    SHOW_LOG_NAME_KEY
     
    static final String
    SHOW_SHORT_LOG_NAME_KEY
     
    static final String
    SHOW_THREAD_ID_KEY
     
    static final String
    SHOW_THREAD_NAME_KEY
     
    static final String
    SYSTEM_PREFIX
    All system properties used by SimpleLogger start with this prefix
    static final String
    WARN_LEVEL_STRING_KEY
     

    Fields inherited from interface org.slf4j.Logger

    ROOT_LOGGER_NAME

  • Method Summary

    Modifier and Type
    Method
    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 param1)
    Perform single parameter substitution before logging the message 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, 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 arg)
    Perform single parameter substitution before logging the message 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 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()
     
    void
    info(String msg)
    A simple implementation which logs messages 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... argArray)
    Perform double 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?
    void
    log(org.slf4j.event.LoggingEvent event)
     
    protected Object
    readResolve()
     
    protected String
    renderLevel(int level)
     
    void
    trace(String msg)
    A simple implementation which logs messages 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... argArray)
    Perform double 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 arg)
    Perform single parameter substitution before logging the message 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 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.
    protected void
    writeThrowable(Throwable t, PrintStream targetStream)
     

    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 Details

  • Method Details

    • renderLevel

      protected String renderLevel(int level)

    • writeThrowable

      protected void writeThrowable(Throwable t, PrintStream targetStream)

    • 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?

    • trace

      public void trace(String msg)
      A simple implementation which logs messages of level TRACE according to the format outlined above.

    • 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.

    • 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.

    • 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.

    • trace

      public void trace(String msg, Throwable t)
      Log a message of level TRACE, including an exception.

    • isDebugEnabled

      public boolean isDebugEnabled()
      Are debug messages currently enabled?

    • debug

      public void debug(String msg)
      A simple implementation which logs messages of level DEBUG according to the format outlined above.

    • 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.

    • 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.

    • 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.

    • debug

      public void debug(String msg, Throwable t)
      Log a message of level DEBUG, including an exception.

    • isInfoEnabled

      public boolean isInfoEnabled()
      Are info messages currently enabled?

    • info

      public void info(String msg)
      A simple implementation which logs messages of level INFO according to the format outlined above.

    • 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.

    • 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.

    • 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.

    • info

      public void info(String msg, Throwable t)
      Log a message of level INFO, including an exception.

    • isWarnEnabled

      public boolean isWarnEnabled()
      Are warn messages currently enabled?

    • warn

      public void warn(String msg)
      A simple implementation which always logs messages of level WARN according to the format outlined above.

    • 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.

    • 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.

    • 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.

    • warn

      public void warn(String msg, Throwable t)
      Log a message of level WARN, including an exception.

    • isErrorEnabled

      public boolean isErrorEnabled()
      Are error messages currently enabled?

    • error

      public void error(String msg)
      A simple implementation which always logs messages of level ERROR according to the format outlined above.

    • 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.

    • 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.

    • 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.

    • error

      public void error(String msg, Throwable t)
      Log a message of level ERROR, including an exception.

    • log

      public void log(org.slf4j.event.LoggingEvent event)

    • getName

      public String getName()
      Specified by:
      getName in interface org.slf4j.Logger

    • readResolve

      protected Object readResolve() throws ObjectStreamException
      Throws:
      ObjectStreamException