Using Log4j with Slf4j

Slf4J (Simple Logging Facade for Java) is a high level logging framework. It serves as an abstraction for various logging frameworks, allowing developers to switch to desired logging framework at deployment time. 

Log4j Configuration File

Shown below is the log4j configuration file to be used for our sample application. It is a regular log4j configuration file.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
    <appender name="console" class="org.apache.log4j.ConsoleAppender">
    	<param name="threshold" value="debug" />
        <layout class="org.apache.log4j.PatternLayout">
	    	<param name="conversionPattern" value="%m%n"/>
    <logger name="examples" additivity="false">
		<level value="debug"/>
    	<appender-ref ref="console"/>
	<level value="debug" />
	<appender-ref ref="console"/>


  • slf-api.jar
  • log4j.jar
  • slf4j-log4j.jar

Java Class

Below is our java class which is using slf4j to capture logging information. The slf4j logger is just an abstraction; log4j loggers are used behind the scene to capture the logging information.

package examples;

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

public class TestLogging {
    public static Logger logger = LoggerFactory.getLogger(TestLogging.class);
    public static void main(String args[]){
   	    logger.debug("This is a debug log message");

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Introduction to Logging with Log4J

Log4j is an open-source logging framework that helps developers to capture logging statements in java applications. It is fully configurable and can be configured using external configuration files.

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