Kotlin:
כתיבה לשגיאה התקנית

fun main() {
    System.err.println("This is an error message!")
}

dependencies {
    implementation 'org.slf4j:slf4j-api:1.7.30'
    implementation 'ch.qos.logback:logback-classic:1.2.3'
}

<configuration>
    <appender name="STDERR" class="ch.qos.logback.core.ConsoleAppender">
        <target>System.err</target>
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>
    
    <root level="error">
        <appender-ref ref="STDERR" />
    </root>
</configuration>

import org.slf4j.LoggerFactory

fun main() {
    val logger = LoggerFactory.getLogger("ExampleLogger")
    logger.error("This is an error log message!")
}