How to setup Logging in Spring Boot

Spring Boot comes with build-in logging functionality and its very easy to integrate.

Logback

Spring Boot uses logback logging framework. Logback in an upgrade of log4j framework.

It comes bundled with spring boot starter packs. For example if we using spring web service, then logback comes bundled with it.

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web-services<actifactId>
</dependency>

Implementation

To use logging in a Java class use below code

Logger logger = LoggerFactory.getLogger(getClass());

logger.error("This is an error");

That’s it !! just two lines. Spring boot makes it that easy !

Log Levels

There are different log levels that we can use with Spring Boot. These are shown below,

logger.trace("This is a trace");
logger.debug("This is a debug");
logger.info("This is info");
logger.warn("This is a warn");
logger.error("This is a error");

Logback configuration

Logback has many configurations. These can be set in application.yml as shown below,

logging:
	file: 
		name:C:/logfolder/logfile.log
	pattern:
		file: '%date{dd MMM yyyy - HH:mm:ss.SSS}'
	level:
		com.example.www:DEBUG

Configurations are set under logging tag in application.yml.

1. The location of the log file and where it will be saved is defined in name tag.
2. The pattern is defined in pattern tag. This defines how the log file will be printed.
3. And level tag indicates from which level the logs will be printed.

In the above example since we have declared DEBUG; debug, info, warn and error logs will be printed.

If we had declared TRACE, then logs marked trace, ,debug, info, warn and error logs would be printed.

There are many other configurations, that can be done to Spring Boot logging. More information can be found here.

That’s how we can implement logging in Spring Boot. For more articles on Java click here.