Log4j Program

Create New Project:

Log4j

Log4j

Log4j

Click on finish and project will get created.

No create new file log4j.poperties in src folder of your project.

Log4j

Log4j

Click on finish and file will get created.

Place below mentioned code in that file: Here logging is set for both console and file.

# Root logger option
log4j.rootLogger=INFO, file, stdout
 
# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=D:\logs\logging.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.MaxBackupIndex=0
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=
                    %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
 
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=
                 %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

Log4j

Create One new folder in Your project with name lib and place log4j-1.2.16.jar in that folder:

Log4j

Add jar in classpath:

Log4j

Now create new java class in your project:

Log4j

Java Code:

import org.apache.log4j.Logger;

public class LoggingExample {

	private static Logger log = 
	         Logger.getLogger(LoggingExample.class);

	public static void main(String[] args) {
		
		log.trace("Trace Log Message");
		log.debug("Debug Log Message");
		log.info("Info Log Message");
		log.warn("Warn Log Message");
		log.error("Error Log Message");
		log.fatal("Fatal Log Message");
	}

}

Now run your application and see output in console and file:

Log4j

Log4j