How to Programmatically Change Logback's Root Logging Level?

How can I change the root logging level in Logback programmatically when a specific event occurs?

<configuration debug="true"> 
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> 
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="debug">
        <appender-ref ref="STDOUT" />
    </root>
</configuration>

The ability to change the logging level of Logback programmatically is useful in various scenarios, especially when debugging or in production environments. This guide explains how to adjust the root logger level from debug to error dynamically upon the occurrence of specific application events.

import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;

public class LoggingExample {
    public static void main(String[] args) {
        // Example: Change root logging level on a specific event
        changeLogLevel("ERROR");
    }

    public static void changeLogLevel(String level) {
        LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
        Logger rootLogger = loggerContext.getLogger(Logger.ROOT_LOGGER_NAME);
        rootLogger.setLevel(ch.qos.logback.classic.Level.toLevel(level));
        System.out.println("Root logging level changed to: " + level);
    }
}

Causes

• A specific event triggers a need to suppress debug information.
• Conditional logging levels based on application states or critical failures.

Solutions

• Create a method that updates the root logger's level.
• Use the `LoggerContext` to modify the logging configuration dynamically.

Mistake: Forgetting to cast `ILoggerFactory` to `LoggerContext`.

Solution: Ensure you import the right classes and perform the correct casting as shown in the code snippet.

Mistake: Not testing the logging level change effectively in different scenarios.

Solution: Implement comprehensive tests to check various logging levels and ensure proper functionality.