logback - no applicable action for [root] - logback

Question

i just started with Java and i'm trying to configure the logging via logback.
The logging does not work, instead i get an an error in the console:
-ERROR in ch.qos.logback.core.joran.spi.Interpreter#9:29 - no applicable action for [root], current ElementPath is [[configuration][appender][root]]
so no appender is found:
-WARN in Logger[Test01] - No appenders present in context [default] for logger [Test01].
My code is very simple:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MainClass {
public static void main(String[] args) {
Logger log = LoggerFactory.getLogger(MainClass.class);
log.debug("test"); }
}
Complete console output when running looks like this:
08:41:43,047 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml]
08:41:43,047 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy]
08:41:43,047 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Found resource [logback.xml] at [file:/C:/Users/klein/IdeaProjects/Maven01ArtifactId/target/classes/logback.xml]
08:41:43,196 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
08:41:43,199 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
08:41:43,209 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
08:41:43,235 |-ERROR in ch.qos.logback.core.joran.spi.Interpreter#9:29 - no applicable action for [root], current ElementPath is [[configuration][appender][root]]
08:41:43,235 |-ERROR in ch.qos.logback.core.joran.spi.Interpreter#10:41 - no applicable action for [appender-ref], current ElementPath is [[configuration][appender][root][appender-ref]]
08:41:43,235 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.
08:41:43,235 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator#78e94dcf - Registering current configuration as safe fallback point
08:41:43,235 |-WARN in Logger[Test01] - No appenders present in context [default] for logger [Test01].
I'm using IntelliJ Community 2018.3 and started a project with Maven. logback.xml and pom.xml are below.
Any ideas what is wrong here?
logback.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<configuration debug="true">
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</encoder>
<root level="DEBUG">
<appender-ref ref="STDOUT"/>
</root>
</appender>
</configuration>
pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>xxx</groupId>
<artifactId>xxx</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<slf4jVersion>1.7.25</slf4jVersion>
<logbackVersion>1.2.3</logbackVersion>
</properties>
<dependencies>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4jVersion}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>${logbackVersion}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logbackVersion}</version>
</dependency>
</dependencies>
</project>

Answer 1

In logback.xml, you put the <root> section inside the <appender> section.
Your logback.xml should be:
<?xml version="1.0" encoding="UTF-8" ?>
<configuration debug="true">
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</encoder>
</appender>
<root level="DEBUG">
<appender-ref ref="STDOUT"/>
</root>
</configuration>