Set root logging level in application.yml

You can use ROOT to configure the root logging level:

logging:
  level:
    ROOT: DEBUG

You can even use your classname to configure logging level:

logging:
  level:
    com.yourorganization.Yourclass: DEBUG

If you want level by package, you can use this syntax :

logging:
  level:
     org.springframework.web: DEBUG
     guru.springframework.controllers: DEBUG
     org.hibernate: DEBUG
     org: INFO

It's an old question, but I just had this problem.

While setting

org.springframework.web: debug

or

org.hibernate: debug

works fine, if you want to do the same for your project files (setting level per package), you have to use wildcards. So, for the example in the question, it would be:

logging:
    level:
        root: WARN
        com.filenet.wcm.*: ERROR
        de.mycompany.*: DEBUG

Alternatively, you can set the logging level per class without using wildcards, as shown in torina's answer.