Home > Articles > Programming > Java

  • Print
  • + Share This
Like this article? We recommend

Changing the Log Level

Now let's look into how the defaults are set for the Logger object. Look in the jre/lib directory of your Java Runtime Environment installation for a file called logging.properties. This file is used for customizing the logging level and other logging details at runtime. Copy the file into your work directory and call it mylogging.properties. Below is a truncated sample listing of the logging.properties file.

#---------------------------------------------
#  Default Logging Configuration File
#---------------------------------------------
#  Global properties
#---------------------------------------------
handlers= java.util.logging.ConsoleHandler
#---------------------------------------------
# Default global logging level.
.level= INFO
#---------------------------------------------
# Handler specific properties.
#---------------------------------------------
# Limit the messages that are printed on the console to INFO and above.
java.util.logging.ConsoleHandler.level = INFO
java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter

Alternatively, you can cut-and-paste the properties specified above and save them as the mylogging.properties file.

As seen above, the logging Level both globally as well as for the specific ConsoleHandler is set to INFO. Change the level as specified below:

.level= ALL
java.util.logging.ConsoleHandler.level = FINER

Here we're setting the global Level to ALL (log all message), but for the ConsoleHandler we're choosing the Level as FINER. This implies that the console should ignore messages lower in priority than FINER. To run the application now, use the following command to specify that you want to override the default logging.properties files:

java -Djava.util.logging.config.file=mylogging.properties SimpleLogging

The resulting output on the screen may be as follows:

Jun 12, 2002 6:08:29 PM SimpleLogging main
SEVERE: Something really bad happened
Jun 12, 2002 6:08:29 PM SimpleLogging main
WARNING: This is a warning
Jun 12, 2002 6:08:29 PM SimpleLogging main
WARNING: This is also a warning
Jun 12, 2002 6:08:29 PM SimpleLogging main
INFO: Just for your info
Jun 12, 2002 6:08:29 PM SimpleLogging main
CONFIG: A configuration message
Jun 12, 2002 6:08:29 PM SimpleLogging main
FINE: A fine message
Jun 12, 2002 6:08:29 PM SimpleLogging main
FINER: A finer message
  • + Share This
  • 🔖 Save To Your Account