Spring boot’s default logging uses Logback which is included as a transitive dependency. Spring Boot supports Log4j2 for logging configuration if it is on the classpath and Logback has been excluded.
1. Maven
First, remove spring’s default logging dependency (spring-boot-starter-logging) and then add log4j2 dependency (spring-boot-starter-log4j2).
Spring will automatically configure log4j2 once it finds its jar files in the classpath.
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
</dependencies>
2. Add log4j2.properties File in /resources Folder
Now we have to add log4j2.properties
or (log4j2.xml
) in src/main/resources
folder. That’s all.
You can refer to log4j2 properties file example for more detailed configuration options.
status = error #The level of internal Log4j events that should be logged to the console.
name = PropertiesConfig
filters = threshold
filter.threshold.type = ThresholdFilter
filter.threshold.level = debug
appenders = console
appender.console.type = Console
appender.console.name = STDOUT
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
rootLogger.level = debug
rootLogger.appenderRefs = stdout
rootLogger.appenderRef.stdout.ref = STDOUT
3. Demo
Now add a few log statements in the application and see the logs in configured appenders e.g. I configured console and file.
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.context.ApplicationContext;
@SpringBootApplication
public class Application extends SpringBootServletInitializer {
private static final Logger LOGGER = LogManager.getLogger(Application.class);
public static void main(String[] args)
{
ApplicationContext ctx = SpringApplication.run(Application.class, args);
LOGGER.info("Info level log message");
LOGGER.debug("Debug level log message");
LOGGER.error("Error level log message");
}
}
Check the output.
2018-06-01T13:55:42.506+0530 INFO Info level log message
2018-06-01T13:55:42.506+0530 DEBUG Debug level log message
2018-06-01T13:55:42.506+0530 ERROR Error level log message
Let me know if you have any questions about the configuration of spring boot log4j2 properties.
Happy Learning !!