Logger setLevel() method in Java with Examples

setLevel() method of a Logger class used to set the log level to describe which message levels will be logged by this logger. The level we want to set is passed as a parameter. Message levels lower than passed log level value will be discarded by the logger. The level value Level.OFF can be used to turn off logging. Log Levels: The log levels control the logging details. They determine the extent to which depth the log files are generated. Each level is associated with a numeric value and there are 7 basic log levels and 2 special ones. We need to specify the desired level of logging every time, we seek to interact with the log system. To know more about Log Levels, refer this Log Levels in Logging. Syntax:

public void setLevel(Level newLevel)
              throws SecurityException

Parameters: This method accepts one parameter newLevel which represents the new value for the log level. Return value: This method returns nothing. Exception: This method throws SecurityException if a security manager exists, this logger is not anonymous, and the caller does not have LoggingPermission("control"). Below programs illustrate the setLevel() method: Program 1: Java

// Java program to demonstrate
// Logger.setLevel() method

import java.util.logging.*;

public class GFG {

    public static void main(String[] args)
        throws SecurityException
    {

        // Create a logger
        Logger logger
            = Logger.getLogger(
                GFG.class.getName());

        // Set log levels
        logger.setLevel(Level.FINEST);

        // Print log level
        System.out.println("Log Level = "
                           + logger.getLevel());
    }
}

Output: The output printed on console of Eclipse is shown below- Program 2: Java

// Java program to demonstrate
// Logger.setLevel() method

import java.util.logging.*;

public class GFG {

    public static void main(String[] args)
        throws SecurityException
    {

        // Create a logger
        Logger logger
            = Logger.getLogger(
                GFG.class.getName());

        // Set log levels
        logger.setLevel(Level.WARNING);

        // Print log level
        System.out.println("Log Level = "
                           + logger.getLevel());
    }
}

Output: The output printed on console output is shown below- Reference: https://docs.oracle.com/javase/10/docs/api/java/util/logging/Logger.html#setLevel(java.util.logging.Level)