logback: How to change the logging level of root logger programmatically?

Below snippet can be used to update the logging level of root logger programmatically.

ch.qos.logback.classic.Logger rootLogger = (ch.qos.logback.classic.Logger) LoggerFactory
.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
rootLogger.setLevel(Level.WARN);

 

Find the below working application.

 

Step 1: Create new maven project ‘update-root-logger-logging-level-programatically’.

 

Step 2: Update pom.xml with maven dependencies.

 

pom.xml

 

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.sample.app</groupId>
	<artifactId>update-root-logger-logging-level-programatically</artifactId>
	<version>1</version>

	<dependencies>

		<dependency>
			<groupId>ch.qos.logback</groupId>
			<artifactId>logback-classic</artifactId>
			<version>1.2.10</version>
		</dependency>


		<dependency>
			<groupId>ch.qos.logback</groupId>
			<artifactId>logback-core</artifactId>
			<version>1.2.10</version>
		</dependency>

		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>1.7.36</version>
		</dependency>


	</dependencies>
</project>

 

Step 3: Create logback.xml file under src/main/resources folder.

 

logback.xml

 

<configuration>

	<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>

Step 4: Define HelloWorld application class.

 

HelloWorld.java

package com.sample.app;

import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ch.qos.logback.classic.Level;

public class HelloWorld {

	private static void sleep(int noOfSeconds) {
		try {
			TimeUnit.SECONDS.sleep(noOfSeconds);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	private static void printLogMessages() {
		Logger logger = LoggerFactory.getLogger(HelloWorld.class);
		logger.trace("Trace message");
		logger.debug("Debug message");
		logger.info("Info message");
		logger.warn("Warning message");
		logger.error("Error message");
	}

	public static void main(String[] args) {

		printLogMessages();

		System.out.println("\nSleeping for 2 seconds\n");
		sleep(2);

		ch.qos.logback.classic.Logger rootLogger = (ch.qos.logback.classic.Logger) LoggerFactory
				.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);
		rootLogger.setLevel(Level.WARN);

		System.out.println("\nUpdated root logger logging level to WARN\n");
		printLogMessages();
	}
}

Total project structure looks like below.

Run HelloWorld.java class, you will see below messages in the console.

10:10:26.422 [main] DEBUG com.sample.app.HelloWorld - Debug message
10:10:26.423 [main] INFO  com.sample.app.HelloWorld - Info message
10:10:26.423 [main] WARN  com.sample.app.HelloWorld - Warning message
10:10:26.423 [main] ERROR com.sample.app.HelloWorld - Error message

Sleeping for 2 seconds


Updated root logger logging level to WARN

10:10:28.424 [main] WARN  com.sample.app.HelloWorld - Warning message
10:10:28.424 [main] ERROR com.sample.app.HelloWorld - Error message

 

You can download complete working application from below link.

https://github.com/harikrishna553/java-libs/tree/master/logback/update-root-logger-logging-level-programatically

 

 

 

Previous                                                 Next                                                 Home