Setting up logback in Java and Scala project

Logback is promising log library I think, So in this time, I am going to set up logback in Java and Scala project using maven.

Setting up logback is quite straitforward and simple.

At first, you have to download maven dependencies.

Things to remember you have to, org.slf4j library and ch.qos.logback libraries version should match each other. Otherwise, you have error message during executing program.

In my case, org.sl4j 1.7.5 and logback 1.0.13 are perfectly matched.

<dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>jcl-over-slf4j</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.0.13</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-core</artifactId> <version>1.0.13</version> </dependency>

And then put configuration file to the classpath. (i.e. src/main/resources/logback.xml)

Configuration file is something like below.

<?xml version="1.0" encoding="UTF-8"?> <configuration> <appender name="FILE" class="ch.qos.logback.core.FileAppender"> <file> test.log </file> <encoder> <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern> </encoder> </appender> <logger name="test" level="TRACE"/> <root level="debug"> <appender-ref ref="FILE"/> </root> </configuration>

Finally, create logger instance by LoggerFactory. 

You don't have to learn how to use this library. It's same as log4j. You can use logger like below.

In Scala,
import org.slf4j.LoggerFactory object LogbackTest { val logger = LoggerFactory.getLogger("LogbackTest") def main(args: Array[String]) { logger.debug("Hello Logback") } }

In Java,

public class LogBackTest { private Logger logger = LoggerFactory.getLogger(LogBackTest.getClass()); public static void main(String [] args) { logger.info("Hello logback in Java"); } }