Display Spring-Boot Banner with Root-Logger WARN

I had same problem and just set this property in application.properties:

spring.main.banner-mode=LOG

Now it prints to both console and file, with log level INFO. As long as you have your root log level and appenders set to accept INFO, you will see it.

<root level="info">
    <appender-ref ref="RollingFile" />
    <appender-ref ref="Console" />
</root>

During printing a banner Spring Boot uses logger of class org.springframework.boot.SpringApplication with INFO level.

The simples solution would be to enable INFO level for this particular class:

<logger name="org.springframework.boot.SpringApplication"
        level="INFO" additivity="false">
    <appender-ref ref="FILE"/>
</logger>