Here a working example to use slf4j as façade with log4j in the backend:
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>xxx</groupId>
<artifactId>xxx</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.30</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.30</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.13.3</version>
</dependency>
</dependencies>
</project>
src/main/resources/log4j.properties
# Root logger option
log4j.rootLogger=DEBUG, stdout
# 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
src/main/java/Main.java
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Main {
private static final Logger logger = LoggerFactory.getLogger(Main.class);
/**
* Default private constructor.
*/
private Main() {
}
/**
* Main method.
*
* @param args Arguments passed to the execution of the application
*/
public static void main(final String[] args) {
logger.info("Message to log");
}
}