Logging is a critical part of any application. It can help us debug issues, track events, and monitor performance. The default logging system in Spring Boot is Logback, but we can also use our own custom logging system. In this post, we'll take a look at how to implement a custom logging system in Spring Boot.
Before we dive into how to implement a custom logging system, let's take a step back and understand how logging works in Spring Boot. Spring Boot uses Logback by default for logging. Logback is an excellent logging framework that has many features, such as:
Logback is configured using a file called logback.xml
. This file is typically located in the src/main/resources
directory. The contents of the logback.xml
file can be customized to change the logging behavior of our application. For example, we can change the logging level, add appenders, or change the log format.
Now that we've covered the basics of logging in Spring Boot, let's take a look at how to implement a custom logging system. The first thing we need to do is create a file called log4j2.xml
in the src/main/resources
directory. The contents of this file will be similar to the logback.xml
file, but we'll be using Log4j2 instead of Logback.
Next, we need to add the following dependency to our pom.xml
file:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.11.1</version>
</dependency>
Finally, we need to add the following property to our application.properties
file:
logging.config=classpath:log4j2.xml
This will tell Spring Boot to use our log4j2.xml
file for logging configuration.
In this post, we've seen how to implement a custom logging system in Spring Boot. We've also seen how to configure Log4j2 and how to change the logging level.